Envelope interior reference fileVan Horn, Erica2007Includes 23 category cards (20 x 18 cm.), each with ms. title listing a pattern category (e.g. Triangles & zig zags, Blue words on white, etc.).Includes 3 table of contents cards (20 x 18 cm.), listing in ms. all 23 categories and the number of cards found in each one.Includes 522 cards (18 x 18 cm.), pasted on each of which is a cut section from the interior of an envelope; each card has printed title: Envelope interior number [blank]. Cards numbered in ms. from 1 to 522.three dimensional object