Fly line backing is an essential part of a fly fishing setup. It’s the thin, strong line that connects to the rear end of your fly line, filling your reel and providing extra yardage for when a fish makes a long run. This guide covers everything you need to know about fly line backing, including the different types of backing (materials like Dacron vs. gel-spun polyethylene), how to choose the right backing for your reel and target fish, and some recommended fly line backing products available on Amazon. We’ve structured this guide with SEO-friendly headings and bullet points for easy reading.
Types of Fly Line Backing
The two primary types of fly line backing are Dacron (braided polyester) and gel-spun polyethylene (GSP). Each material has its advantages, strengths, and best uses. Below we break down these types:
Dacron (Braided Polyester) Backing
Dacron is a braided polyester fiber (Dupont’s trade name for polyester) that has been the standard backing material for decades. It offers a reliable balance of strength, diameter, and ease of use. Dacron backing typically comes in 20 lb or 30 lb test strengths, and is used in both freshwater and light saltwater fly fishing.
A spool of 20 lb Dacron fly line backing (in high-visibility orange). Dacron backing is known for its high tensile strength and low stretch . It’s thicker in diameter than gel-spun backing, but this makes it very easy to handle and knot securely.
Advantages of Dacron Backing:
• Easy Handling: Dacron’s larger diameter and supple braided build make it easier to knot and handle, reducing the chances of tangles or line burn on your fingers. It’s a “good compromise between thinness and the ability to make blind splice loops,” meaning you can splice loops or tie knots with confidence . It also lies smoothly on the reel with low memory.
• Durability: Quality Dacron backing is very durable and rot-resistant. It has decent abrasion resistance and can last for years on your reel without breaking down. It also tolerates UV exposure and water well. (For example, Cortland Micron backing is famous for its tight, round braid and smooth, low-friction finish that is “stretch-resistant” and “virtually tangle-free” .)
• Affordable: Dacron is generally more affordable than gel-spun backing. For most trout or bass setups, 100 yards of 20 lb Dacron backing is very cost-effective. It’s the budget-friendly choice that still delivers reliable performance .
• Proven Performance: Dacron has been the go-to backing for decades, so its performance is well-proven. Many anglers stick with Dacron for its consistency and because they rarely actually see the backing when fighting smaller fish.
Disadvantages of Dacron Backing:
• Larger Diameter (Less Capacity): A key downside is the thicker diameter compared to gel-spun lines. Dacron has a lower strength-to-diameter ratio, so it takes up more space on the reel . This means you can fit fewer yards of Dacron on a spool than you could with the equivalent strength of gel-spun backing. If you’re targeting fish that make very long runs, the limited capacity can be an issue.
• Lower Strength for Size: Although plenty strong for most uses, Dacron isn’t as outright strong as GSP. 30 lb Dacron is much thicker than 30 lb gel-spun (and roughly equivalent in diameter to about 50–65 lb gel-spun). If you need ultra-high breaking strength in a small reel, Dacron may not cut it.
• Some Stretch: Dacron backing has a bit more stretch than gel-spun. It’s not overly stretchy (nothing like monofilament), but it does have some give. This can actually be a minor advantage as shock absorption, but it also means slightly less sensitivity and power on really long runs. Gel-spun has virtually zero stretch by comparison.
• Not Ideal for Big-Game Saltwater: For large saltwater species (tarpon, tuna, GTs, etc.), Dacron’s limitations show. Its thicker profile and lower strength mean you might run out of line on big fish. In those cases, gel-spun is often the “upgrade” backing to use.
Best Uses: Dacron backing is best for freshwater fishing and smaller saltwater species. It’s perfect for trout, panfish, bass, steelhead, and light salmon fishing – scenarios where 50–150 yards of backing is plenty. For example, 20 lb Dacron is commonly used for trout and bass, while 30 lb Dacron is used for steelhead, salmon, bonefish, stripers, and similar species . If you have a mid to large arbor reel and are chasing fish unlikely to take you deep into your backing, Dacron is an excellent choice. Its easy handling is especially good for beginners or anyone who wants a hassle-free setup.
Gel-Spun Polyethylene (GSP) Backing
Gel-spun polyethylene backing (sometimes just called “gel-spun”, or sold under brand names like Spectra® or Dyneema®) is a modern superline used for backing. It’s made of extremely strong fibers that allow for much thinner line diameters. GSP backing typically comes in 30 lb, 50 lb, or higher break strengths, and despite those ratings, it’s far thinner than Dacron of lower break strength. This type of backing is popular in saltwater fly fishing or anytime you need maximum line capacity and strength on the reel.
Label of a 300-yard spool of 30 lb gel-spun backing. Gel-spun polyethylene lines are ultra-thin for their strength, allowing anglers to pack 50–75% more backing onto a reel compared to standard Dacron . This high-capacity backing is favored for saltwater and big-game fly fishing.
Advantages of Gel-Spun Backing:
• High Strength-to-Diameter: Gel-spun is incredibly thin for its break strength. For example, 30 lb gel-spun backing is much smaller in diameter than 20 lb Dacron , yet stronger in tensile strength. You can pack a lot more yards of GSP onto a reel. This is crucial for species like bonefish, tarpon, permit, salmon, or steelhead that might run well over 100 yards. In fact, gel-spun backing provides “up to 60% more capacity than Dacron” of the same strength , and some brands claim even 75% more in capacity due to its micro-diameter .
• Extremely High Tensile Strength: GSP fibers are many times stronger than steel by weight . That means a relatively thin gel-spun line can have a very high breaking strength (50 lb, 80 lb, etc.). This gives you a huge safety margin when fighting big fish. The backing is unlikely to be the weak link in your setup. Anglers pursuing record-class fish often use 50–80 lb gel-spun backing to ensure the backing won’t snap before the leader or fly line in a long battle.
• Small Diameter = Fast in Water & Less Drag: The thin diameter also cuts through the water with less drag and puts up less resistance if there’s current. If a fish takes off, the smaller line reduces drag in the water (and on the reel), which can be beneficial. The small diameter also means your reel’s spool will have slower RPMs on a long run, reducing the chance of reel over-spin, and it enables faster retrieval rates when you crank the line back .
• Minimal Stretch: Gel-spun backing has virtually no stretch (near-zero). This means solid hook sets at long distance and direct pressure on a running fish. There’s no sponginess – every inch you gain or lose is direct. Many anglers appreciate this sensitivity and immediacy when fighting strong fish.
• Abrasion and Water Resistance: Despite being thin, good GSP backing is highly abrasion-resistant and durable. It’s usually made of HMPE fibers (the same type used in braided fishing superlines), which handle abrasion and wear extremely well . It also “retains 100% of its strength while in the water” and is unaffected by UV, gasoline, oils, salt, etc. . In other words, it’s very stable and won’t rot or weaken over time. This makes it great for harsh saltwater environments.
Disadvantages of Gel-Spun Backing:
• Expensive: The advanced materials and construction make GSP backing more costly per yard than Dacron. If you need hundreds of yards, the price adds up. For example, gel-spun backing often costs roughly 2–3 times as much as equivalent lengths of Dacron (though prices vary by brand). The investment is often worth it for the performance, but budget-conscious anglers may opt for Dacron if the extra capacity isn’t required .
• Slippery – Requires Special Knots: Gel-spun’s slick, thin profile makes it trickier to knot securely. Standard knots can slip out if not tied properly. Many anglers use a doubled loop (Bimini Twist) or double-wrap arbor knot to secure GSP to the reel and a strong loop-to-loop connection to the fly line. The low stretch and slickness mean you must tie very snug, secure knots. It’s not difficult with practice, but it’s less forgiving than Dacron. (Tip: Use a Bimini Twist in the backing to create a loop, as it’s proven to be one of the strongest knots for gel-spun .)
• Handling Caution: The thin diameter of GSP can cut into your skin under tension. You should never wrap gel-spun backing around your hand or fingers when a fish is pulling – it can act like a razor. Using gloves or being very cautious when handling the line is wise. Additionally, if wound improperly, the line can dig into itself on the reel under heavy pressure, potentially leading to snags. Laying it evenly and tightly on the spool during installation helps prevent this.
• No Stretch (Double-Edged Sword): While zero stretch gives sensitivity, it also means no shock absorption. If a fish makes a sudden hard surge, there’s less give in the backing, putting more strain on your rod, reel drag, and knots. Anglers compensate by using smooth drags and slightly more forgiving rods or leaders. It’s usually not a deal-breaker, but something to be aware of – there’s little elasticity in the system once you’re into the backing.
• Not Spliceable (Solid core): Unlike Dacron, which is usually hollow braid and can be spliced, most gel-spun backing has a solid or tightly woven core that cannot be spliced easily . This means you can’t perform spliced loops in the line itself; you must rely on knots for loops or connections. (There are specialized hollow-core gel-spun lines that allow splicing, but those are niche products.)
Best Uses: Gel-spun backing is ideal for saltwater fly fishing and big-game species. Whenever you expect fish to run long and fast – think bonefish on the flats, tarpon, permit, sailfish, tuna, muskies, king salmon, etc. – GSP backing is the top choice. It’s also great on small reel setups where capacity is limited. For example, if you have a mid-sized reel rated for 100 yards of 20 lb Dacron, you could instead load it with 30 lb gel-spun and possibly fit 150–160 yards, giving you extra cushion for long-running fish . Many anglers use 30 lb gel-spun as a direct upgrade to 20 lb Dacron (since 30 lb GSP is still thinner). Heavier 50 lb is used for big saltwater reels and heavy-duty scenarios. In summary, use gel-spun when you need maximum backing length and strength – it’s the backing of choice for demanding fly fishing adventures where standard Dacron might come up short.
Choosing the Right Backing
Choosing the right fly line backing comes down to a few key factors: your reel size, the species you’re targeting, and the conditions in which you’ll be fishing. Here are some guidelines to help you select the appropriate backing for your needs:
Reel Size & Capacity
Always check your reel’s specifications for backing capacity. Reels often list how much backing they hold (e.g., “WF6F line + 100 yd of 20 lb backing”). Use this as a baseline. If your reel has limited capacity and you need more line, consider using gel-spun backing to increase the yardage. For example, a reel that fits 100 yards of 30 lb Dacron might hold ~160 yards of 30 lb gel-spun, since gel-spun is much thinner. You want the reel adequately filled (leaving about 1/8 inch of space from the rim when the fly line and backing are on) for optimal retrieve rate. If capacity is not an issue (large arbor reel with plenty of room), Dacron is usually sufficient. Only push to gel-spun if you truly need the extra yards or strength.
Target Fish Species
Tailor your backing choice to the fish you plan to pursue. Smaller fish that make short runs (e.g., trout, panfish, bass) don’t require enormous amounts of backing. In these cases, 50–100 yards of 20 lb Dacron is typically more than enough. Larger or faster species (steelhead, salmon, bonefish, carp, etc.) may routinely run well into the backing, so using 30 lb (or stronger) backing and 150–300 yards is prudent. For big-game fish (tarpon, offshore species, etc.), you’ll want heavy gel-spun backing in as great a length as your reel can hold – sometimes 300+ yards for things like tarpon or GTs. As a rule of thumb, use 20 lb backing for trout, bass, and most freshwater fishing, and 30 lb (or higher) backing for saltwater or big fish . The stronger backing is not just for the extra break strength, but also for the thicker diameter which helps fill large reels and is easier to handle on bigger outfits .
Fishing Environment & Run Potential
Consider the typical fight length in your fishing environment. In small rivers or lakes, fish simply can’t run very far – backing length is less critical. In open water (big rivers, saltwater flats, the open ocean), fish have ample room to run, so backing length becomes critical. For example, a bonefish on the flats can sprint 150 yards in seconds, so anglers often use 200+ yards of backing for bonefish and similar saltwater species. In contrast, a trout in a creek might only take 10–20 yards at most. If you’re fishing saltwater, tropical species, or any situation with long runs, lean towards gel-spun for its capacity advantage . If you’re fishing enclosed waters or targeting species that doggedly fight close, you can lean towards Dacron.
Required Backing Strength
Backing strength typically should meet or exceed the strength of your fly line and leader. Commonly, 20 lb test is used on 3–7 weight outfits, and 30 lb test on 8 weight and above. The idea is that you don’t want your backing to be the weakest link if a fish runs far. In practice, even 20 lb backing is stronger than most trout tippets, so it’s fine for those. But for big-game fish with heavy leaders (20–30 lb leaders or more), 20 lb backing could be a weak link. In those cases, use 30 lb or higher so that if something breaks under strain it’s more likely the tippet or a knot, not your backing line. Heavier backing (50+ lb) is generally reserved for specialized big game scenarios and requires large reels. Match the backing strength to your tackle and target: e.g., 30 lb on a salmon reel, 20 lb on a trout reel, 50 lb gel-spun on a tarpon/billfish reel.
Handling & Experience
If you are new to fly fishing or value ease of use, Dacron is the safer choice. It’s user-friendly – knots hold easily and it’s less prone to tangles. Gel-spun, while not overly complicated, does demand more attention to knot tying (e.g., doubling the line for arbor knots, using sufficient wraps) and safety (to avoid cuts or tangles). If you’re uncomfortable with that, stick to Dacron. On the flip side, experienced anglers who chase large fish might accept gel-spun’s quirks for its undeniable performance benefits.
Fishing Conditions
In addition to open water vs. confined spaces, think about conditions like rocks, coral, or structure. If you expect the backing might rub against rocks or coral (say, running bonefish around coral heads), the abrasion resistance of gel-spun could outperform Dacron (gel-spun is known to be very abrasion-resistant) . However, no backing will last long against sharp rocks – in those cases, maximum strength (and maybe more frequent replacement of backing) is the strategy.
Color and Visibility
Backing comes in many colors (white, orange, chartreuse, blue, neon, even multicolor metered backing). Bright colors like neon chartreuse or orange are popular because they make it easy to see your backing in the water and gauge distance. For example, high-vis backing helps you and others track a running fish, and you can quickly notice when the fish transitions from fly line to backing. Color is largely personal preference and does not affect the fish (the backing is usually not visible to the fish until very far away, and by then the fish is hooked). If you like to keep things stealthy, you can choose more neutral colors (olive, white, etc.), but most anglers go with bright backing for utility. Choose a color you like – it can even be a fun way to color-code different reels or line weights.
In summary, choose backing that fits your reel and your quarry. Err on the side of a little extra backing if you’re not sure – it’s insurance on the reel. And remember, for 90% of freshwater fishing, a good Dacron backing in the appropriate strength will do the job perfectly. It’s only when pushing into very large fish or long runs that you truly need the fancy gel-spun stuff. If in doubt, consult your reel manufacturer’s recommendations and consider the biggest fish you might encounter.
Recommended Products from Amazon
Below is a list of high-quality fly line backing products (in various price ranges) that you can find on Amazon. We’ve included different options to suit everything from trout fishing to saltwater adventures. For each product, we outline the specifications, pros, and cons:
RIO Dacron Fly Line Backing (20 lb / 30 lb)
Material/Type: Braided Dacron (polyester) backing
Strengths Available: 20 lb, 30 lb (common; some in 50 lb)
Lengths Available: Typically sold in 100 yd, 200 yd, 300 yd spools (larger bulk spools also available)
Color Options: Multiple colors – e.g. white, chartreuse, orange, blue, pink. (High-visibility chartreuse or orange are popular choices.)
Price Range: $$ (Moderate; ~$10–$20 for 100–200 yd spools)
Pros:
• Trusted Brand Quality: RIO’s Dacron backing is known for its quality and consistency. It features “high strength and low stretch” and is unsurpassed in quality for a Dacron line . You can rely on it not to fail unexpectedly. Knot strength is excellent, and it’s easy to splice loops if desired.
• Easy to Handle: The line is round and smooth, making it easy to wind onto your reel without snarls. It doesn’t have a “wiry” feel. RIO’s backing is a “super smooth braid” that packs nicely and knots securely . This is great for beginners – you won’t struggle with it.
• Good Balance of Thinness and Grip: RIO’s 20 lb and 30 lb Dacron are a good compromise of diameter – thin enough to get adequate capacity, but not so thin that it’s hard to handle. It’s designed to be “thinness with the ability to make blind splice loops”, meaning you can make strong loop connections easily .
• Multiple Colors & Sizes: RIO offers this backing in a wide array of colors, which is fun for customization and useful for visibility. They also offer spools in different lengths, so you can buy exactly what you need (e.g., a 200 yd spool for a salmon reel, or 100 yd for a trout reel). No need to buy excess.
• Durability: This backing is very durable over time. Anglers report that RIO’s Dacron holds up well to years of use, with minimal fraying or color fading. It’s rot-proof and UV resistant, as expected from polyester backing.
Cons:
• Bulkier than Gel-Spun: As with all Dacron, the 30 lb RIO backing is considerably thicker than gel-spun alternatives of similar strength. If you have a small reel and need maximum capacity, you might run short on space with Dacron. (RIO’s 30 lb Dacron has a diameter around 0.020 inches, whereas a 30 lb gel-spun might be ~0.012 inches.) This is only a concern for big fish or small reels.
• Mid-Range Cost: RIO’s backing is not the cheapest Dacron available. You pay a bit of a premium for the brand name and quality. There are lower-cost no-name options (see below) that are cheaper per yard. That said, RIO is still reasonably priced and the quality control may save you headaches.
• Limited Stretch: This backing has low stretch (which is generally a pro for solid hook sets). But if you prefer a little cushion, note that it doesn’t give much. A sudden jolt isn’t buffered much by the line. However, this is a minor point since most Dacron backing behaves similarly.
• Not for Extreme Saltwater Needs: For most saltwater fishing, 30 lb Dacron is fine. But if you’re chasing truly fast or large game fish (e.g., tarpon over 100 lbs), you’ll likely need more capacity or strength than the 30 lb can offer. In those cases, you’d step up to gel-spun or 50 lb Dacron (which RIO also offers in bulk). Essentially, RIO Dacron is more geared to general-purpose backing than specialized big-game scenarios.
RIO’s backing is a top choice for all-around use. It’s perfect for filling trout and bass reels, and equally at home on a light saltwater setup for bonefish or redfish. With its dependable performance and variety of options, you can’t go wrong keeping a spool of RIO Dacron backing in your tackle kit.
Cortland Micron Fly Line Backing (20 lb / 30 lb)
Material/Type: Braided Dacron polyester (Cortland’s proprietary Micron backing)
Strengths Available: 20 lb, 30 lb
Lengths Available: 100 yd, 250 yd spools (also sold in bulk spools up to 1,200+ yd)
Color Options: Commonly in white, chartreuse, orange, neon green, and other colors depending on retailer.
Price Range: $$ (Moderate; comparable to RIO. Slightly higher per yard in some cases due to premium branding)
Pros:
• Premium Quality & Legacy: Cortland Micron is often called “the standard by which all fly line backing has been judged for more than 50 years.” It’s a tried-and-true backing that has earned the trust of generations of anglers. The braid is extremely tight and uniform, which gives it a slightly thinner diameter and higher capacity than many other Dacron brands . It’s world-famous for its “tight, round braid, smooth low-friction finish and stretch-resistant performance.” In practical terms, Micron often tests stronger than its rated strength and behaves impeccably on the reel.
• Zero Twist, Tangle-Free: Cortland’s manufacturing process ensures the backing has no line twist and lays flat. It’s virtually tangle-free right out of the package . This means when you’re spooling up, you won’t be fighting twists and kinks. It also packs very evenly on the reel without lumps or flat spots.
• Excellent Knotting and Splicing: Micron’s construction makes it very easy to work with. Because it’s a hollow braid, you can splice loops into it if you wish (many big-game anglers splice a loop instead of tying a knot for maximum strength). It’s also known to “knot perfectly every time.” Whether you’re tying an Albright knot to your fly line or an arbor knot to your reel, Micron cinches down securely with high knot strength.
• Durability & Longevity: This backing is made in the USA with high-quality Dacron fibers . It’s built to last – resistant to rot, UV, and abrasion. Anglers often report using the same Micron backing on a reel for many years and many fish without it weakening. It’s a set-and-forget component once spooled.
• Smooth, Low-Friction Finish: Micron has a very smooth coating which gives it a slick feel. This helps it flow through rod guides with minimal resistance. If a fish is stripping off backing at high speed, the low-friction finish is gentle on the guides and doesn’t generate as much heat. This also contributes to its abrasion resistance.
Cons:
• Higher Cost: Cortland Micron is generally a bit more expensive than generic backing. You pay for the reputation and USA manufacturing. For example, a 250 yd spool might cost a few dollars more than a competitor’s. It’s not exorbitant, but if you’re backing multiple reels, the cost difference adds up.
• Limited Color Selection: Micron traditionally came mostly in white and high-visibility chartreuse. In recent years Cortland has added more colors, but depending on the retailer you might not find as many color choices as with RIO or others. This is a minor con, but if you really wanted a specific color, availability can be patchy.
• Availability in Pre-cut Lengths: Cortland typically sells 100 yd and 250 yd spools in consumer packaging. If you needed, say, 150 yards, you’d have to buy a 250 and use a portion (or find a shop that will spool by the yard). Some other brands sell 150 or 200 yd spools. Not a big issue, but you might end up with extra unused backing unless you plan carefully.
• Same Material Limitations: Being Dacron, Micron shares the same general limitations as any Dacron backing. It’s thicker and lower in capacity than gel-spun, and has a bit of stretch. These aren’t Micron-specific cons, just traits of the material. If you need ultra-thin backing, you’d skip Dacron altogether.
Overall, Cortland Micron is a top-of-the-line Dacron backing. It’s an especially great choice if you want the assurance of a long track record and USA-made quality. Micron is often the pick of serious anglers who have “seen their backing more than most” – a testament from those who battle big fish into the backing frequently . If you value reliability and are willing to spend a few extra dollars, Cortland Micron will serve you extremely well.
Piscifun Braided Fly Line Backing (20 lb / 30 lb)
Material/Type: Braided polyester Dacron backing (high-strength, 8-strand hollow braid)
Strengths Available: 20 lb, 30 lb
Lengths Available: 100 yd, 300 yd (common retail spools; also sold in 500 yd in some cases)
Color Options: Usually sold in bright solid colors like white, orange, fluorescent yellow, and blue. (Some options have two-tone combinations.)
Price Range: $ (Budget-friendly; roughly $8–$15 range for most spool sizes, making it one of the best values)
Pros:
• Affordable Value: Piscifun backing is known for giving you a lot of bang for your buck. It’s often significantly cheaper than big-name brands, yet still well-reviewed. You can fill multiple reels without breaking the bank. Despite the low cost, it doesn’t sacrifice quality – which is why it’s a #1 Best Seller in fly line backing on Amazon (high volume of satisfied users).
• Strong & Abrasion-Resistant: This backing is braided with high-strength polyester fibers and a tight 8-strand weave. It is “extremely abrasion-resistant” and not prone to fraying . Many anglers report that it performs just as strong as more expensive backing. The 30 lb test in particular gives a lot of confidence; it’s tough and holds up under stress.
• Hollow Core & Low Stretch: The backing has a hollow braid construction (like other Dacron), meaning you can splice it if needed. It also has low stretch, so it won’t compromise hook sets. Piscifun explicitly notes the backing is “rot proof and UV resistant”, indicating good long-term durability .
• Easy to Knot: Users find that knots hold well with this line – it has a slightly “soft” feel that cinches nicely. The line packs tightly without cutting itself. According to product info, it “has good curl degree and is easy to knot, won’t damage your fly rod guides” . In practice, this means you can tie your usual backing knots (Arbor knot, Albright, etc.) and expect them to hold firm.
• Multiple Colors & Visibility: Piscifun offers several bright color choices (like neon lime green, orange, etc.), which are great for visibility. The colors are noted as “colorfast” (resistant to bleeding or fading), so you won’t end up with dye all over your hands or gear. Pick a color that contrasts your fly line for easier tracking.
• Available in Large Spools: One advantage Piscifun has over some premium brands is the availability of 300 yard spools at a low cost. If you have a large reel or multiple reels, you can get 300 yards in one pack (often for under $15) which can be split as needed. This is very convenient for saltwater anglers who might use 250+ yards on a single reel.
Cons:
• Less Brand Prestige: Piscifun is a newer, budget-oriented brand. While it has a strong following, it doesn’t have the decades-long reputation of RIO or Cortland. Some anglers might be hesitant simply because it’s not a “big name.” However, the sheer number of positive reviews has largely proven its reliability in the real world.
• Slightly Stiffer Feel: A few users report that this backing can feel a tad stiffer or wire-like out of the package compared to premium backing which is very supple. This might be due to a coating or the braid tightness. That said, once wound on the reel under tension, it usually conforms well. Any initial stiffness doesn’t seem to impact performance much.
• Color Selection Variances: While Piscifun offers multiple colors, individual listings might be limited to two or three options. For example, one spool length might only come in chartreuse and orange. If you’re picky about color, you may have to shop around or be flexible.
• Bulk Packaging: This is a minor point, but some Piscifun backing is sold in simple packaging (just a plastic bag or basic spool) rather than a nice spool with a holder. Be careful when opening it to avoid tangles. It’s wise to spool it onto your reel directly from the factory coil under tension to prevent any loose loops.
In summary, Piscifun fly line backing is one of the best budget choices on the market. It’s especially great if you need to outfit several reels or want extra backing length without spending a lot. Despite being inexpensive, it is “strong and sturdy” – the 8-strand braid design gives it reliability comparable to higher-end Dacron . This backing is an optimal choice for trout, bass, salmon, or even light saltwater use where you want to save money but not compromise on performance. Many anglers have switched to Piscifun (or similar brands) and been pleasantly surprised at how well it holds up.
Cortland Gel-Spun Polyethylene Backing (30 lb / 50 lb)
Material/Type: Gel-spun polyethylene (GSP) backing – braided from ultra-strong PE fibers
Strengths Available: 30 lb, 50 lb, 80 lb (higher strengths have slightly larger diameters)
Lengths Available: 300 yd spools are common; also available in bulk 2500 yd spools (for pro shop or multiple reel use)
Color Options: High-visibility colors like bright yellow, pink, blue, and white. (Colors are solid, and white is a neutral option.)
Price Range: $$$ (Premium; approximately $35–$60 for a 300 yd spool depending on strength, brand, and retailer)
Pros:
• Ultra-Thin, High Capacity: Cortland’s gel-spun backing is exceptionally thin for its strength. Using this backing can dramatically increase the yardage your reel holds. For example, 300 yards of 30 lb GSP takes up about the same space as 100–150 yards of 20–30 lb Dacron . This backing is specifically designed so that “the tight, round braid allows you to pack a lot of backing onto small spools.” If you have a small or mid-size reel and need extra capacity (or you want to be prepared for a marathon run from a fish), this is a top solution.
• Superb Strength and Quality: Cortland is a leader in line technology, and their gel-spun backing is braided to exacting specifications . It’s made from “super-high-strength” fibers that give it incredible tensile strength for its diameter. In equal diameters, this gel-spun is many times stronger than steel . The 50 lb, for instance, is extremely robust – great for big tarpon or GTs. The line itself is very tough and “extremely high abrasion resistance” is a noted feature (Scientific Anglers, who also make GSP backing, claim 100% strength retention when wet and imperviousness to UV, salt, etc., which applies to all quality GSP lines) .
• Smooth and Low-Friction: The finish on Cortland’s GSP backing is slick, which helps it shoot through rod guides without damage. The backing has “a very low coefficient of friction so it will not damage your fly rod guides” . This means when a fish is running fast and your backing is zipping out, you don’t have to worry about grooving your guides or the line heating up excessively. It’s gentle on gear despite its strength.
• Big Game Ready: This backing is built for big fish. It’s the choice on many saltwater anglers’ reels for species like bonefish, permit, tarpon, and tuna. The availability of 50 lb and 80 lb test versions means you can go after seriously large game with confidence that your backing won’t fail. Even the 30 lb (because of its no-stretch nature) is strong enough to stop a hard-charging fish as long as your knots hold. Essentially, it turns your fly reel into something more akin to a big-game reel in terms of line strength.
• Color Visibility and Options: The high-vis colors (neon yellow, hot pink, etc.) are excellent for seeing how much line is out and which direction a fish is moving. Cortland offers multiple colors so you can customize or use a different color on different reels to distinguish setups. The color is bonded to the fibers well (minimal bleeding). Also, a neat trick some anglers do with gel-spun: because it’s so thin, they might use a metered or two-color approach (e.g., 150 yd white then 150 yd orange) to know when half the backing is out. With Cortland’s options, you can achieve that by splicing two colors if desired.
Cons:
• Higher Cost: Gel-spun backing is expensive relative to Dacron. Cortland’s GSP is a premium product, and you’ll pay accordingly. If you only need 100 yards of backing for trout, it’s not cost-effective to use GSP. This product is aimed at situations where its performance justifies the price. The upfront cost is higher, but keep in mind you generally don’t need to replace backing often – it can be reused for many years, so it’s a one-time investment per reel.
• Knot Care and Slippage: Like all gel-spun lines, proper knots are crucial. Because it’s so slick and thin, knots like a standard arbor knot can slip if not tied with extra wraps or a backing knot (some anglers tape the line to the spool arbor as an extra precaution against slippage). It’s recommended to use a Bimini Twist to create a loop in this backing and then loop-to-loop to your fly line, as this has proven to retain the most strength . These extra steps mean rigging gel-spun takes a bit more time/skill. If knots aren’t perfectly tied, you risk failure under heavy load. There is less margin for error than with Dacron.
• Handling Safety: Gel-spun backing demands respect when a big fish is pulling hard. Never grab the line tightly or wrap it around your hand; it can cut. With Cortland’s 50+ lb strength, this line under tension is strong enough to cause injury if mishandled. Use your rod and reel drag to fight the fish – not your palm on the line. Some anglers also note that gel-spun can “bite” into itself on the spool if the line is not wound under uniform, high tension. So when spooling it, apply steady tension and pack it tightly. This will prevent the line from later burying into softer loose coils.
• Limited Stretch and Give: As mentioned, no stretch can be a double-edged sword. If a fish suddenly stops or surges, something can break. You’ll want a quality drag system on your reel to compensate, and perhaps slightly more forgiving leader class just in case. With gel-spun, the backbone is unforgiving – either a pro or con depending on your perspective. It puts more onus on the angler to fight the fish smoothly.
• Overkill for Small Fish: If you’re not actually targeting fish that need this backing, it’s an unnecessary expense and complication. Some anglers get lured by the “tech” aspect and put gel-spun on everything, but truthfully for 90% of trout and bass fishing, you’ll never see the backing or need this level of strength. In fact, thicker Dacron might be better in those cases because it fills the reel and prevents your fly line from getting too deep into the arbor. So, consider whether you truly need gel-spun or if it’s just nice to have. Save it for when it matters.
Cortland’s gel-spun backing is a top-tier choice for serious saltwater and big-fish anglers. It provides peace of mind and extra ammunition for battles with fish that would otherwise spool a reel loaded with standard backing. When you’re chasing that fish of a lifetime and every yard counts, this backing delivers the capacity and strength you need . It’s been tested on everything from bonefish to billfish. Just be sure to pair it with solid knots and good technique. If you’re gearing up for a saltwater trip or trophy hunt, Cortland GSP backing is worth the investment for its superior performance.