ANSI X9.100-10-2016 establishes paper specifications for the MICR documents that are used in the US Payments System. While checks and deposit tickets are the primary documents considered in these specifications, users of MICR/OCR E-13B font readers will be well served by applying these specifications to internal documents, when intended for use in reader/sorters. This standard gives specifications to those attributes most important and most common both to raw base stock and to finished printed products of MICR documents. When available, methodology for measurements of the various paper attributes shall conform to those of the Technical Association of Pulp and Paper Industry (TAPPI). The specifications state what are considered to be the appropriate requirements for paper documents intended for external processing from the viewpoint of the end user, namely the institution performing post encoding in proof-of-deposit applications and those that operate reader/sorter equipment for inclearing and transit clearing applications. Nonetheless, these same specifications are also considered appropriate requirements for paper before any print process is applied to base stock. Base stock, either from rolls or from sheets, must meet the specifications as well as fully processed, end user documents. Paper specifications from the standpoint of fraud prevention and security are not given within this standard. The various features that paper can have that hinder fraud and aid authentication of original document are addressed in ANSI X9.100-170 Check Fraud Deterrent Icon standard and in X9/TR-8 Check Security Guideline. Although reference may be made within this standard to various commonly used paper-based security features, setting specifications for paper-based security features are excluded from the scope of this standard.