Here is a more natural stone gridblock that you can bucketfill to add a more natural grid for a map. I will suggest adding a texture above it and put it on overlay. It will lighten up then.
Free for personal use and with friends when an rpg is involved. Ask if you want to use it beyond that. I will probably say yes.

4x4_50px_Gridblock_Bucketfil_v1b_hopemaps.png

If any of you are interested, I added an even bigger one with more variety, a texture and better shading on my patreon page under Journeyman and up.



P.S.
I added this one to the first page of the thread.
4_Gridblock_Bucketfil_v1_hopemaps.png