I keep fabric scraps from flea market finds in my studio for exactly this reason. Canvas doesn't have to be just paint. The question is whether the material adds something true to the piece or just decorates it. When texture comes from what the work needs rather than what looks interesting, you feel the difference.

I've tried tissue paper and pressed leaves in a few small pieces. The texture holds a moment in a way paint alone doesn't, like bringing back the actual air of a place. What materials are you thinking about?