There are actually various different ways you could create a rustic look to your acrylic pieces. For example, on my "Dream" acrylic bookmark, I've used some alcohol inks (ie. cranberry, espresso, butterscotch and silver mixative) to colour it using the alcohol ink applicator. Only add the silver mixative alcohol ink after you've added all the others. It makes it look a little rough, unfinished or textured.
An easier or alternative way to doing it would be to simply get yourself a metallic acrylic paint dabber. For example, as per my layout about, I've inked an acrylic deco frame from Clear Scraps with some copper paint dabber. Why paint dabber? The texture on the dispenser (sponge) would create a rustic look to your pieces instantly. If you don't have a paint dabber, try using some sea sponges or uneven sponges.
Try to create some rustic look to your acrylic projects!
Clear Scraps DT Member