Oh no!
First off, I love Penny Black stamps. Unbeatable quality, or so I thought. The first time I used this stamp, I used a clean, dry, clear acrylic block. The stamp worked fine and I actually stamped several images. However, when I went to remove the stamp from the acrylic block, most of the image transferred to the acrylic block. I had to use goof off to clean up the mess. Now the stamp image is so faint, I have to look at the actual stamp to see what it is. I had the same issue with another recent stamp I purchased from Penny Black as well. The good news it that it does not affect the stamped image in any way.