you need an eraser. You can use white vinyl erasers, green rubber
erasers, or hard red rubber ("Pink Pearl") erasers.
people prefer to carve vinyl ("Staedtler-Mars") erasers
because they cut easily and make a clear, bold impression.
for thin-line, finely detailed stamps, I prefer the hard red erasers.
Experiment and see what works best for you.
need bigger stamps, you can buy special carving
blocks from a craft supplier.