Doctor's blade flaws in photogravure

[Rein]

In photogravure, the little holes of which the design of a stamp is made of were meant to keep the ink, an area in the design without a "screen" of holes would lose the ink immediately while the cylinder turned. This screen is absolutely necessary but can be replaced by a set of diagonal lines that can hold the ink long enough till the ink sets on the paper and delivers the required design!

Bu the cylinder would also keep the ink stuck outside the holes for awhile, long enough to reach the paper and in that case the design would get blurred and smudgy! To avoid that a special, long and lean knife scrapes the superfluous ink off the cylinder without being able to get the ink out off the holes! This was called the "doctor's blade" in English or "Rakel" in German"or "racleta" in Spanish. The German word for photogravure is Rakeltiefdruck...

If the mechanism of the doctor's blade gets defective, the ink will be present - in a haze often - on the stamp. If the blade itself gets defective, with little indents in it, the indents of the blade will result in longish coloured lines, more or less following the direction of printing, the turning of the cylinders.

to be continued ...

[Rein]

In the 20p Nahuel Huapi lake this looks like a "normal" doctor's blade flaw! And maybe it is indeed!





to be continued ....

[Rein]

In the 20p Nahuel Huapi lake this looks like a "normal" doctor's blade flaw! And maybe it is indeed!

But when you find a stamp with these doctor's blade flaws and also a very similar one or even two more of them??????




to be continued ....

[Rein]

to be continued ....

[Rein]

to be continued ....

[Rein]

Three so far of the mate importado [Wiggins Teape uncoated paper with a parallel watermark and the asymmetrical paper wire, direction of paper vertical!] out of the circa 100 used copies....

to be continued ....

[Rein]

the coated Zárate paper [asymmetrical paper wire, orthogonal watermark, direction of paper horizontal]

to be continued ....

[Rein]

the coated Zárate paper [asymmetrical paper wire, orthogonal watermark, direction of paper horizontal]

Again almost or completely the same lines! Two copies out of the circa 50 coated ones!

This can NOT be a coincidence! Doctor's blade flaws with the same positions in 5 different stamps on two diffrent types of paper in two different periods!

The direction of printing of all 20p stamps is the ink flowing to the LEFT, so this could have been OK as doctor's blade flaws, BUT it is a complex cylinder-position characteristic with a yet unknown position on the sheets. Or to say it in traditional philatelic terms: a PLATE FLAW.

A Plate Flaw that hasn't been described in Argentine philatelic literature .....

to be continued ....