Proofs also exist on many of the APO-NEDA printed stamps of the mid 1980s. It is believed that they were spirited out by employees of the production facility and sold to unsuspecting collectors as imperforate errors. The estimated quantity on available issues range from a sheet or two for each issue. Lesser quantity available on printer's waste and color proofs. Likewise several of the imperforate proofs exist with favor first day of issue cancels.