Please Specify Horizontal or Vertical Pairs

US Imperforated stamps.  Taken from ‘Presentation Sheets of 6-8 sheets per Presentation Sheet. These imperfs are from selected issues, not every issue is imperforated.   (Scott is now listing  these imperfs). The different combinations are Singles, Pairs, Gutter Pairs and Blocks, Plate Blocks, the rare Gutter Center Cross blocks and full Sheetlets.  The last time the US issued Imperforated stamps was the Farley National Parks issues.