Testing product

So I have some friends who are very much into their books, and attend conventions to get books signed. I am playing with the idea of creating and selling some designed bookplates.

I wanted to know what sort of designs you would want on a bookplate, and if color or just black and white. I see they are normally sold in a pack of 5, and if you want a variety pack in that 5 or 5 of the same?

Could use some feedback while I find a sticker manufacterer that offers a white crate paper sticker. Glossy or even the vinyl matte finish would not hold pet or marker so well.