hi, does anybody know of any 120 oversized sleeves (the ones that fit 12 frames of 6x7 in 4 rows by 3 frames in each row) that are as thick as the ones that fit 9 individual 6x7 frames? i have a set from clearfile and theyre the same thickness as my 35mm ones. the 9 indivudal sleeves are very thick, 8 mil polypropylene to be exact (according to bh). pana-vue says theirs are heavy duty but no specificied thickness. anybody?