If you mail accounts payable checks or payroll on a monthly basis, these checks are the time-saving solution. All our pressure seal checks are printed on 29# security paper that includes toner adhesion technology, invisible fluorescent fibers, brownstain and three-family chemical sensitivity. These checks also have SecureScan, opaque Security Mark on the back of the check, logo line in the endorsement area and a warning band above the check area as notification of original document.