You could create an image with enough space to accommodate your canvas and reference to one side.
You can use any brushtip with the clone engine, but not the lightness features. You can emulate impasto effects though using layered effects with an appropriate brushtip. Values in the sampled area would also be applied - so the illusion of thickness could also occur that way.
I used a clone brush in the still-life images I posted a while ago, but I sampled a palette rather than an existing image. It might help to have a look at those, and the layered impasto explanation linked to in there if it’s relevant to what you want to achieve.