Wednesday, April 18, 2012
Burgess article on the printing process
In the 1924 Australian Philatelic Review (pp. 5-6) J. H. Burgess wrote an article entitled Manufacture of Copper Plates for the Printing of Queensland Stamps where he described in part the process that occurred in the printing of the Queensland 1st Sideface issue. I have reproduced the relevant parts of the article here.
Much has been written on this subject, and a very great amount of thought has been concentrated on the unravelling of the methods of manufacture, and the make-up of the plates used for the surface printing of the Queensland ,stamps. The initial error, which has caused trouble to philatelists, is the statement in Mr. Basset Hull’s history that the Queensland printer had only a small bath suitable for treating one mould containing four impressions only, and the inference drawn therefrom that he had only one bath. There were two baths in the establishment, each capable of holding several such moulds at one time, so that as many as six blocks of four could be deposited at the one time.
The same baths were used to deposit the larger "60" and "40" electro blocks in 1897 and subsequent years. Batteries were at first used, but later a dynamo was installed. It will thus be evident, that more plates were prepared than has been chronicled, but which fact has been suspected and practically proved by many learned philatelists. There were several moulds in the 1879 issue carefully detailed by Mr. Bornefield. Also several moulds of the 1882 issue. The 1887 issues are particularly indicative of at least four moulds, as outlined by Captain C. W. Crawford in the London “Philatelist.” Later issues indicate the same thing. As the population increased and the demand grew for stamps, more and more plates had to be produced which necessitated the quicker manufacture of plates than a single-mould bath would allow.
When we know that a whole one penny plate was destroyed and rendered useless in half a day, by the action of the printing ink on the copper, and there was no shortage of stamps recorded, it is clear that plates could be manufactured quickly. I have been informed by the official who made the plates that the apparatus existed, as previously mentioned. The reason for making such small moulds was the great difficulty of stripping the copper, which was built up to the thickness of thick drawing paper. A large number of these electrolytic deposits were failures. This was due to the use of lead moulds for depositing upon: To enable bettor stripping, 'the mould was first coated with a thin skin of zinc. It is also asserted that current density caused trouble in this respect.
The copper blocks were cleaned with muriate of zinc on the back, heated, and coated with zinc until deep enough for the printing frame. These blocks were planed, 'trued up, and fitted together as uniformly as possible, sometimes having to be spaced with stiff drawing paper to get the correct register for the perforating machines. The lack of stiffness of such a plate caused the plate to gradually work out of register to such an extent that the perforator could not punch in between the various stamps. This was remedied by uncoupling the blocks, truing up, and re-packing it. It was this, more than anything else, which caused the regrouping of the plates and eventually led to the use of the larger electros. The blocks of four were, of course, put together in any order after truing and cleaning, no care being taken to group them in 'the same order again. Several instances of this have been found. After some years, the Government Printer was prevailed upon to alter the methods, and larger moulds were made in 1897.