Nice Great Britain Graphite Line Find

Here's an interesting find. Scott 320c is stated as 2p red brown with one line on right, as seen from the back. Stanley Gibbons lists this as 564. What is nice is that Stanley Gibbons also mentions a version with the line on the left, which is what I have below, right-hand stamp (SG 564a).



My 2010 catalog lists the normal used stamp at 2.25, but the special variety at 225 pounds. Not too bad for a US$1.00 purchase.

Very nice, Partime. To us that have no idea about graphite lines, can you tell us what they are used for?

Peter

According to SG, "these were used in connection with automatic sorting machinery, first introduced experimentally in Southampton in December, 1957".

The lines were printed on the back, before gumming. I am not quite sure how a line on the back can be picked up by automatic sorting equipment which, presumably, scanned from the front. I'll leave that to one of our British experts.

Graphite conducts electricity, so it has something to do with that. The lines allowed detection of the stamp so it was also used for orientation ("facing") for proper cancellation as well as detecting the mail class.

I am pretty sure that the graphite lines would be recognized magnetically. In the early days of computers, graphite rings were used as computer memory. A 'write' wire through the ring would induce a magnetic field in the ring and 'read' wire would detect this field and interpret it as a digital 1 or 0.

OK, recognizing magnetically makes sense. Checking for orientation, also makes sense, but of dubious value to the post office. I guess there is still a question since most of the issues had two bars, and only the 2d was printed with one bar. How is the post office to determine if the correct value was actually put on the stamp?

Anyway, these are difficult to show in the collection, since you have to flip them backwards to show the difference. I just mount them with a normal copy facing up to show the front side.

The envelope is mechanically flipped and turned so it can be cancelled by a single canceller. A worker doing this job is a thing of the distant past or is limited to tiny post offices.

Hate to say it, but the graphite line of the right hand stamp does not match the one on the left. Different width, different black and doesn't look like a graphite color. Take a magnifier and look at the edges of the perf tips where the line crosses them. Is there ink soaked into the paper there as it seems to be? That can't happen with graphite lines, which were applied before perforating. Compare with the same area on the left-hand stamp.

The pic on the right is ink not graphite; you can see many spot where the ink was absorbed by the paper. Look like a marker pen

I think our detectives have turned my expensive find into a forgery. Below is a close-up of the front of the stamp, at the lower perf. The "graphite line" has soaked through to the front, indicating ink, not graphite. Thanks to everyone for their input. Great links also ...

Sorry to be a killjoy, but it is what it is. For the dollar, this goes into the "lessons learned, glad I didn't spend $25" category.

This is kind of like hunting mushrooms in the wild, believe it or not. You learn the look of a couple of the edible types as best as you possibly can. If what you find doesn't match exactly, you don't pick it. It may or may not have killed you, but it's not worth the risk finding out. So it is with overprints, cancels and suchlike.