I got mine online from
http://www.jencaputo.com . She's nice & had great customer service.
Product is called PVA, "a PH neutral professional quality adhesive, dries acid free. Solvent free & water soluble. For bookbinding & paper projects."
Her card keeper kits are pretty cool too, which is how I found her in the first place. She just shows the kits on the first page, you have to chosse one of the links to "Shop the store" or some such.