Just looking at Supreme Littleness Designs website & saw this:
Slap on the Texture?
The look of some MDF and card models will be greatly enhanced with some sort of textured paste spread over them. There are many examples of models with added texture on this site. A simple tile grout from a DIY shop is recommended. Tile grout is a sandy cement that adds a gritty look to the flat surface of MDF. Artists’ acrylic medium or modelling paste is perhaps more expensive but much easier to paste on fibreboard. The wax and resin binders of the MDF can resist a dry grout. Adding water or PVA can help but can also make the texture smoother than desired. Acrylic medium is available in many grades of grittiness and is as simple to paste on as acrylic paint as it is just paint without pigment.
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