Caption on verso reads: "Some useful information for collectors and collators."
Consists of 1 card, printed on both sides, in clear plastic sleeve. On recto is table with columns A-Z representing 23 standard printing signatures for books from the hand-press period, and rows "1s", "2s", "4s", etc., through "32s", representing standard printing formats. Matching signature column with format row gives total number of pages that should be present in books with that collation.