These are my favourite for stamp making. You always get a deep stamp, which I prefer.
Quick brief of why I needed this. To make a silver clay pendants with fine lines and printed logo lettering. It took 3 attempts to get it right. I ended up having to double up on the ink jet print out from their own recommended sheets, IE: printing the same thing twice and then exactly overlaying the printouts to get a perfect black so no light got through. Once I finally got my perfect imprint on the sheet, I went to make a silicone mould of it using the mini moulding compound sold here..... Heres where it all went wrong, it must have some chemical reaction that slows down or stops entirely the moulding compound from curing...Wasted the whole tub trying... I ended up having to use a UV based resin I bought a few years ago to make a mould. Thats just a heads up if you want to use it for making other moulds, other than that its pretty good, 4 stars if your not wanting to make a mould of it :) 1 star if you do.... **** RESPONSE FORM METAL CLAY **** Hi anonymous reviewer, I'm not sure I understand what you are trying to do. If you get in touch we'd be happy to help you come up with a solution. Having to double up your film isn't unusual. It isn't because of the film, it is how black your printer prints. If I make very fine lined stamps, I always double up, or go round the print out with a fine tipped Sharpie to add to the blackness. If the black is the slightest bit grey, or translucent, it will let through light, ruining your stamp. You can play around with your printer settings to enhance the black, or simply print two copies on the sheet and double them up. I'm not clear why you used moulding compound, so my advice here might not be much use. However, I would have reversed the stamp when I made the stamp, so I could use that directly onto the metal clay, rather than trying to make one and then turn it round using moulding compound. I've never applied the moulding compound to a stampmaker stamp, so not sure how well it works. It can also react to if the stamp was cold and wet (after washing it). IF you use moulding compound on the stamp, I'd probably recommend you leave the stamp to dry overnight as the polymer will have absorb some water. Also, if it hadn't been fully cured, or washed out completely, there would still be uncured polymer which would very likely react to the moulding compound. Sounds like you have worked your way through everything, but if you need any more help, just let us know! :)