Giving more pressure to one side of the acrylic block than the other. This results in an image that can be sketchy, splodgy, and have overblown lines all in one image. To help avoid this you want to be using an even work surface. For me the ideal stamping surface is a sturdy desk or table and something with a little bit of give under your project, like a piece of fun foam or a magazine. Also, use an acrylic block that is an appropriate size for the image you are stamping. It is much harder to stamp with even pressure using a 6×4 block with one 1×2 image on it. Make your process easier and use a smaller block.