Inset track sections
9mm gauge (N gauge track)
small stones(suit HO/OO scales)
Long strip(65cm) of inset panels which fit over sleepers, to cut to length . Designed to fit Peco track but might fit other makes.
Could be used to infill points and crossovers.
They should fit over sleepers easily, but might need trimming.
Suitable for straight, curved and flexi track.
Suggest using PVA glue to fit down.
If track is already ballasted, ballast will need removing before fitting panels.
Intended to go between rails, but can also be fitted to outside of rail.
more 3d printed models from Recreation21 here