i think its like that for other colors, but since youre painting black over it, and the original color is closer to black than white, it mihht be better the way she did it. white might set you back ;)
Of course you can! It's even better if you do this in my opinion because you actually read the books. It's great to upcycle them into something useful instead of them sitting around and collecting dust or throwing them into the landfill. Did you see what was on the books in the inspiration books? You can also look on Etsy for what other sellers stamped onto their book spines. Any ideas on what you're gonna stamp? Happy crafting!
Fun fakt: The word Hocus Pocus actually comes from church services, which were held in latin hundrets of years ago. Almost noone understood it and that's why the phrase "Hoc est enim corpus meum" (for this is my body) - which were Jesus words during the last supper - was totally misunderstood. People only saw that apparently bread was turned into Jesus body and that's why "hocus pocus" is describing magic, enchantment and witchcraft.