I have ordered full-sheet matboards, and a plethora of framing supplies, from http://framingsupplies.com/ for the past couple of years. Their min. matboard order is a bit off-putting, but if you are doing alot it will pay off, and you can mix in acid-free foamcore for the framing backs. Good luck w/the process! Adrienne Moumin***************************************on the web at: http://www.picturexhibit.comSaatchi Gallery: http://tinyurl.com/hw6r3Art DC: http://tinyurl.com/vtjqf***************************************