I used an odd sheet of paper for this. I don't remember where I got it from but it was thick and seemed lovely quality. However it was very absorbent and the ink sank in very quickly so that when I painted over it it didn't bleed as I'd hoped and the black lines were too dark. I tried all sorts of things to remedy it, including white soft pastel to soften the lines. Decided I didn't want the initials on the bottom case after I'd inked them so collaged a tissue paper label over the top and added another to the top case. All in all a bit of  a hotch potch but I have managed to save it from going in the bin!