This little image (120 x 160mm) was painted in acrylics on hardboard textured with an acrylic gap-filler called Permafill from Selleys. The stuff is relatively cheap, and as well as making a good texture base similar to heavy gesso, it can also be used as a crude impasto paste by mixing it with acrylic paint. It dries white on its own, but it doesn't affect colour intensity as much as one might expect when mixed with pigment. It's certainly a hell of a lot cheaper than proper acrylic impasto gels.