Home Up Technical 1962 1963 Xmas64 1965 Birds

Technical

Only two print-sheet formats exist for Chambon printings.

bulletMedium. 5 rows of 12
bulletLong. 4 rows of 12

 


print direction
^^^^^^^^^^^^^^

Unlike previous printing methods; a continuous reel of paper was used during printing. The width of the paper roll was a fixed 13 inches.

Irrespective of the layouts, a fixed window of 12x6 inches was available for step and repeat camera work. Thus half inch left and right margins.

Cylinder sizes.

Cylinder layout corresponded to the post office sheet. That is, one complete rotation of the cylinder produced one post office sheet PLUS an inter-sheet gutter. The comb perforator operated on this continuous paper roll. This meant that the interpane gutter, separating each printed sheet, was also the exact size of a stamp.

Vertically, it should be noted  that 4 'long' stamps exactly matched 5 'medium' stamps in height.  Long format cylinders were slightly larger to accommodate the extra height of the interpane blank gutter, which needed to be the same size as it's stamp in order for the continuous comb perforator to operate correctly.

wpe10C.jpg (30074 bytes)
Portrait 5 x 12 medium format Landscape
wpe113.jpg (26909 bytes) wpeFE.jpg (10889 bytes)
Portrait 4 x 12 long format Landscape
Note that the actual printing layouts are portrait oriented.

 

Serial Numbers

Two print heads were used. Each printing alternate panes. One printhead was positioned 2 units in, the other 3 units in, from the lower right corner.

There is no significance to these numbers, they were individually set to random values at the beginning of a print run and were used internally for gross audits.

Autotrons

Autotron Multicoloured, photogravure printing consists of using one to several separate cylinders, each responsible for an individual colour ink. The fast drying inks are printed by each cylinder in turn as the continuous roll passes under it.

Along the left side of some issues are coloured bars or lines. As experience grew, these were introduced to detect the proper operation of each colour cylinder and that the flow of ink was correct. The earliest issues did not have these autotrons. In the case of reprinted values, such as the 2/5d Wren, the later white paper printing (which was confusingly issued first) has autotrons, the cream paper does not.

Perforations

Only one perforator gauge was used, 13x13. Naturally, on Landscape (upright) images the measurement is 13x13.

 

Home Up Next