Aftermarket parts take an aircraft kit a level beyond what the box can offer. Photo-etched frets, decal sheets, canopy masks, resin cockpits and turned metal undercarriage legs all replace simplified styrene with detail that an injection mould physically cannot produce. You can browse by type of part or by scale, from 1:144 through to the large 1:32 and 1:24 formats.
Below we explain where to begin, how to tell whether a set actually fits the kit on your bench, and which of the sub-categories are worth opening first.
Kit designers have to compromise with injection moulding. Seat harnesses end up embossed into the seat cushion, the instrument panel is a flat plate with a decal, and aerials come out several times too thick. Aftermarket parts exist to fix exactly those weaknesses. Photo-etched parts, meaning a thin brass or steel fret, supply fine grilles and fittings; resin castings replace cockpits, engines and wheels; decals open up a different camouflage scheme; and self-adhesive masks keep canopy framing crisp when you spray. The range covers etched frets, pre-painted instrument panels, stitched fabric belts and resin castings from established specialists.
Starting out with aftermarket? Begin with masks and decals: neither needs a new technique and the result is immediately visible. Etched parts call for a little practice with tweezers and cyanoacrylate, while resin conversions assume you are willing to cut and fill. The old counter wisdom still holds: one upgrade finished properly beats five started.
A set has to match both the ratio and the mouldings, which is why manufacturers name the exact kit it was designed around in the product title. The same aircraft from a different toolmaker will not necessarily take it, because part dimensions differ. On 1:48 and larger models an interior upgrade earns its keep; in 1:72 masks, decals and fine aerials usually give more for the money.
Look at your kit first. Better-equipped editions include etch and masks as standard, and you only buy them separately for the cheaper basic boxings. That one check stops you paying twice for the same thing.
Whatever you add, choose it for one specific model. The full listing of kits by scale is under plastic aircraft model kits.