I need a small block of Harrow perforated stamps to illustrate the different types of perforation and seperations in my "Philatelic terms and phrases collection. could anyone tell me the Stanley Gibbons catalogue numbers of anyrelatively inexpensive Harrow perforated stamps, please. Until I looked in the archives of Stamp community I hadn't seen any examples of Harrow perforation. would I be right in thinking that 19th century stamps that look as though they have been perforated by a hungry mouse are probably examples of Harrow perforations?
As mentioned, in Harrow perforation, the whole sheet is done in one stroke. According to "Stamp Collector's Handbook", by Samuel Grossman (13th printing, Feb 1973):
"HARROW: All the perforations are evenly balanced throughout the entire sheet as well as in all the corners."
In comb perforation, there might be slight irregularities where the combs meet. However, perfectly applied comb perforation would look just like Harrow perforation, so this only tells if it not Harrow, but not if it is Harrow.
I would guess that Harrow is unusual, maybe only on stamps issued in small sheetlets.
Thank you for your responses. Using Hornungs Illustrated encyclopedia of Stamp collecting. Hamlyn 1970. I had arrived at the same solution. looking through the archive of the Stamp production process forum. Someone showed a sheet of stamps from an Indian feudatory state (Bhopal?) that were supposed to be Harrow perforated, There some perfs in the lines were visibly out of line. I wonder whether he was mistaken in thinking the perfs were Harrow perfs and they had been done by a line perforation. I have found two photos of Czech miniature sheets done by Harrow perf and will probably have to discover a catalogue number for these and get one for my collection.