Match the cover to the finished sheet size, tab allowance, binding edge, and orientation. Classic Laid covers by size include letter, half-letter, oversize, index-allowance, legal, tabloid, A3, and A4 formats. Exact-size covers suit plain text blocks, while wider formats can protect tabs or create a deliberate border. Confirm the largest internal component before ordering and consider whether the document must fit a folder, mailer, shelf, or storage box. A complete sample will reveal whether the chosen dimensions protect the contents without adding unnecessary width or height. Measure after all tabs, dividers, folded inserts, and backing sheets have been added. Confirm the dimensions against any folder, mailer, shelf, or presentation case used after binding.