Nylon filament, ranked by £/kg

Tough, slippery and demanding

Nylon (polyamide, PA) is the choice for parts that need to survive real mechanical abuse: gears, living hinges, bushings, brackets under load. It is impact-resistant, wear-resistant and self-lubricating, and it bends a long way before it breaks.

It is also the most demanding common filament, and the reason is water.

Drying is not optional

Nylon is extremely hygroscopic — it can absorb enough moisture from the air in a single humid afternoon to print badly. Wet nylon steams in the nozzle, producing rough, bubbled, weak parts and visible popping as it prints.

In practice this means: dry the spool before use (typically 65 °C for six hours or more), and print from a dry box rather than an open holder. A dryer that holds the spool while printing is the right tool here, and this is the material that justifies buying one — see do you need a filament dryer.

Adhesion is the other problem

Nylon does not want to stick to standard build surfaces. Garolite (G10) is the traditional answer and works well; a PEI sheet with a glue stick is a common alternative. Expect to experiment more than with PLA.

Settings to start from

Nozzle 240–270 °C, bed 70–90 °C, cooling low or off, enclosure strongly preferred to limit warping. Nylon shrinks as it cools, so large flat parts need the same care as ABS — brim, slow first layer, no draughts. Those nozzle temperatures also mean an all-metal hot end: a PTFE-lined one degrades above roughly 240 °C, which is inside nylon’s normal range. See PTFE tubing and enclosed versus open-frame printers.

When nylon is the wrong answer

Nylon is the right material for load-bearing, sliding and repeatedly flexed parts, and the wrong one for almost everything else. It is dimensionally less predictable than PETG as it absorbs moisture in service, it is difficult to glue, it takes paint poorly, and it is nobody’s choice for appearance.

• Most functional parts. PETG does the job with none of the drying, adhesion or enclosure trouble. Try it first and only move to nylon when PETG has actually failed.
• Heat resistance without mechanical abuse. ASA is far easier to live with.
• Stiffness rather than toughness. A glass- or carbon-filled nylon, or PETG-CF if the loads are moderate — unfilled nylon is relatively floppy, which surprises people.
• Open-frame printer, no dryer. Then nylon is not a purchase, it is a project.

Buying notes

Nylon costs more per kilo than the mainstream filaments, and glass- or carbon-filled variants cost more again while being considerably stiffer and less prone to warping. Any filled nylon is abrasive and needs a hardened nozzle — see hardened versus brass.

Buy sealed, and open the bag only when you are ready to dry and print it.

How to read this table

The per-kilo column is the only number that compares listings honestly. A spool sold at 40% off can still be poor value, and a multi-spool bundle looks expensive until you divide by its total weight. We count bundles at their full weight, so a 4 × 1 kg pack and a single 1 kg spool sit on the same scale.

Where a listing does not state a usable weight we leave the per-kilo figure blank rather than guessing — a wrong ranking is worse than a missing one.