High grade natural gum rubber. Did we get your attention? Although you may not know exactly why that's important, just know that it's what makes Deep Red Stamps awesome. You'll enjoy better ink transfer on a wide variety of surfaces, and that means great looking stamping on all your layouts and cards. Their stamps are mounted on repositionable foam and cling-mount to any acrylic block. Shop Deep Red Stamps at Scrapbook.com and discover their amazing detail and quality!