Still fond of keeping it natural, this is a wooden grainy pattern engraved on itself through two 13-axes mirroring of its own duplicates and then utilizing layer modes to make it look like it's been carved by a human being with a knife.
No trees have been harmed in the making of this post ;)
Here are three variations from the process.
Please feel free to use these for any project you like.
Created in Affinity Photo.