What is that glue used on credit cards when they come in the mail?

I’m making magnet cards and I need the magnets to pop right off the card – but stick there while in transit – I can’t find the right glue to stick ‘em in place!?
I’m not making credit cards! Duh

It’s actually called "Fugitive Glue" (but most of us in the business call it "Booger Glue") If you can’t find the real thing, rubber cement is a good alternative, but it can damage some papers. If you’re mailing a large number of pieces, you can purchase it at http://www.glu-stix.com/shop/page/product_detail/Product/24a8b1b94b2c8ce448edf3d10539c3fa.html