5 Underrated 3D Printing Filaments Worth Trying

Most people's filament rotation starts and ends with PLA, PETG, and maybe ABS. But there's a small group of materials that solve real problems — better durability, better heat resistance, better skin feel — and they rarely get talked about. Here's a look at five underrated 3D printing filaments, based on The Next Layer's YouTube deep-dive after testing them over several years, plus manufacturer specs where we could verify the numbers ourselves.

Nylon (PA): 3D Printing's Comeback Filament

Nylon has a reputation problem. It warps, it soaks up moisture fast, and it wants a hot nozzle — so a lot of hobbyists skip straight past it. But per The Next Layer's video, the printer landscape has shifted: most printers sold to adult hobbyists now are enclosed CoreXY machines, and nylon doesn't actually need a heated chamber — it's fine with heat from the bed alone.

For people still running open bed-slingers, the video points to two workarounds worth knowing about: Magigoo PA, an adhesive formula made to help nylon stick to an open build plate (with the caveat that you still need ventilation for fumes/VOCs), and specially formulated variants like SUNLU's Easy PA and Polymaker's CoPA, both described as printing successfully on open printers without a chamber. The trade-off that doesn't go away: nylon needs a proper high-temperature filament dryer, ideally one that can hit 80–100°C, because it absorbs moisture aggressively.

TPU-CF and TPU-GF: Fiber-Reinforced Flexible Filament

Standard TPU flexes but never gets fully rigid — even the hardest Shore-A blends still have some give. Adding carbon or glass fiber into TPU changes that math: per the video, TPU-CF and TPU-GF land somewhere between plain TPU and nylon on the rigidity scale, while keeping TPU's strongest traits — durable layer adhesion and high impact resistance — plus a semi-matte finish and some weight savings.

The catch, per the same source: as of the video, only smaller brands — 3DO, Extrudr, Fiberlogy, and Siraya Tech were named — make TPU-CF or TPU-GF; none of the larger filament brands had one in their lineup yet. As with any fiber-filled filament, a hardened steel nozzle is required since the fibers are abrasive.

PC-CF: The Budget Heat-Resistant Filament

If you want serious heat resistance and rigidity without paying PPA-CF or PPS-CF money, carbon-fiber-reinforced polycarbonate (PC-CF) is the material both the video and manufacturer data point to. Prusa's own blog post on Prusament PC Blend Carbon Fiber states a heat deflection temperature of 114°C straight off the printer, rising to as high as 130°C with annealing — numbers that hold up whether you're looking at a hobbyist review or the manufacturer spec sheet. Prusa also notes PC-CF is about 5% lighter than unmodified PC Blend and prints with less warping, which is why (per The Next Layer) some print farms run it on open, unenclosed printers with good ventilation rather than fully enclosed machines.

The real-world trade-offs, confirmed by Prusa's own pros/cons list: you need a hardened steel nozzle (carbon fiber is abrasive enough to chew through brass), the filament has lower impact toughness than non-fiber PC, and it costs more per spool — Prusa's own 800g spool of Prusament PC-CF lists at $59.99. The video names Prusament, Spectrum Filaments, and YXPOLYER as brands it had good results with, though it also notes PC-CF isn't as widely available as more common materials yet.

TPU Air and PEBA Air: Foamed Flexible Filaments Explained

A newer class of flexibles uses active foaming to cut weight and change texture. Siraya Tech's own product page for its Rebound PEBA Air describes tunable hardness from 70A to 95A depending on print temperature (higher temp = softer, lower temp = firmer), up to 50% weight reduction versus solid TPU/PEBA, and a soft matte surface the company markets toward wearables and shoe applications. At the time we checked, Siraya Tech listed an 800g spool at a sale price of $57.39 (regular $69.99) — worth double-checking current pricing before you buy, since spool pricing shifts.

The Next Layer's take lines up with the marketing: the material feels notably better against skin than regular TPU, one spool lasts longer because you're printing with a lot of internal air compared to a denser 500–750g TPU spool, and it's useful anywhere you'd otherwise reach for EVA foam — gaskets, cushioning, insulation. The downside noted in the video: these filaments take real tuning to dial in, especially without automatic pressure-advance calibration built into your printer/slicer combo.

PETG-CF: A Redemption Story for PETG Filament

PETG has a rough reputation among some print veterans — stringing, an inconsistent glossy finish, and moisture sensitivity are common complaints. The video argues that adding carbon fiber addresses most of that list directly: reduced nozzle "boogers," more consistent rigidity, a satin rather than glossy finish, and less of the bubbling that comes from PETG's moisture absorption. It also references reports elsewhere online about carbon fiber weakening some filaments (PLA specifically was named), but states PETG's strength holds up reasonably well with carbon fiber added.

On pricing, the video's creator cites SUNLU selling PETG-CF at $19.99/kg, with Polymaker and Bambu Lab priced under $30/kg — those are the creator's own figures from testing/shopping, not numbers we independently verified against current retailer listings, so treat them as a snapshot rather than gospel. PETG-CF needs only a hardened steel nozzle — no special chamber or other equipment beyond that.

Should You Actually Switch?

None of these materials replace PLA or PETG for everyday prints — they solve specific problems. Nylon and PC-CF make sense when a part needs to survive real abuse or heat exposure. TPU-CF/GF and the Air-series flexibles matter if you're designing wearables, gaskets, or anything needing rebound without full rigidity. PETG-CF is worth a look if you already like PETG's ease of printing but want a better finish and less stringing. As always with a niche or newer filament, start with a small spool, check your printer's max nozzle temperature and whether you have (or need) a hardened nozzle, and read the specific manufacturer's spec sheet rather than assuming every brand's version behaves identically.

Category: Filament Guides