which backs to get?

[troyer16]

Just wondering your guys opinions on which backs to get for my matts?

http://www.matcutter.com/catalog.php?catid=38&styleid=1&parentcatid=2&parentstyleid=1&parentcatname=BACKS

http://www.redimat.com/products/supplies_mounting_board/fbs_board.html

why the large price difference?

for the first, 10 12x16 backs would be $22 yet for the same only $9.10 at the second link?

[PhotosGuy]

The first link has acid free archival covering on the foam core, which may make the difference in price.

[troyer16]

Thanks photosguy,
From the second links store here are the acid free ones
http://www.redimat.com/products/supplies_mounting_board/afbs_board.html
still only $12 for the same 10.

[troyer16]

any other ideas?