Inherited Stamp Identification

About 20 years ago I inherited my mother's stamp collection. In going through it recently I came across a puzzling stamp that I have not been able to identify. Can someone please help?

It is a gutter margin, not a stamp. The printing was done to prevent the use of the paper for forgeries. This looks like a gutter margin from a mill sheet of a Great Britain King Edward VII 1d stamp.

NSK, Brilliant! Thank you very much!

The picture is not too good, but it looks like the colour of the printing is red (carmine). If it is another colour, it was another value.

If it's not the 1d red, it's the 4d orange. Either way, it seems to be perf 15 x 14, not perf 14, and therefore a late printing from 1911.

NSK says that the bars between the panes were added to prevent forgery, but I think that the "Jubilee" lines in the gutter would have been adequate to prevent such forgery. Perhaps the bars were added to reduce potentially damaging pressure on the clichés adjacent to the gutter. NSK, do you have evidence to prove me wrong?

Indeed, it could be orange. The picture is so bad that, on my screen, it shows somewhat reddish. However, the more I look at it, the more orangey it appears.

I agree it is perforated 15 horizontally, so it is the Harrison printing with perforation 15x14.

Most bicoloured stamps did not have these pillars, which would question the function of either a method to prevent fraudulent use of the stamp-sized gutter and the prevention of damage to the clichés. Since the Jubilee Lines on all stamps are closest to those clichés, they would have served to prevent such damage as well.

The plates for the 10d stamp had another layout where the central gutter was two stamps high and perforated through the centre. These gutters also had a watermark. Here it has been established that the pillars served to prevent fraudulent use:



In this case, the pillars were not part of the plates. In the other cases that had them as in the OP, they were.

Jubilee lines were used on issues printed by Great Britain but not necessarily stamps for use in Great Britain. I am not certain how many countries' issues may have the lines but I do know they were used for Palestine issues between 1918 and 1948. These are the styles used:

C and F have no Jubilee lines. The Jubilee lines are the solid lines that run around each pane of stamps. They were named for 1887 permanent stamps issue of the United Kingdom on which they first appeared. As these stamps were issued in the same year that Queen Victoria celebrated here diamond jubilee, the stamps became known as the "Jubilee Issue."

Both the pillars and the Jubilee lines appear on stamps of other countries.