Lithography, Offset, Offset/Litho, Photo/Offset

I recently joined the British North American Philatelic Society which
gave me access to the Elizabethan II study group and their newsletter
Corgi Times.

In the May – June 2019 of the Corgi Times there is an article by Leopold Beaudet and Robin Harris
of their tour to the Lowe-Martin printing plant located in Ottawa.
The article mentions that Lowe – Martin has several lithographic
printing presses.
It uses a ten-colour Heidelberg Speedmaster sheet-fed press to print
sheet and booklet stamps.
Also a seven-colour narrow web-fed 10" wide press specially for
printing coil stamps.
The article has an excellent description of the lithographic process,
explaining how the printer uses 10-micron stochastic screening for
colour shading and that each colour needs a separate plate which are
made from thin 1/16th inch aluminum sheets.

One image in the article shows the 1995 45c definitive and using
it to compare half-tone screening and stochastic screening.
That definitive was first printed by Leigh-Mardon of Australia, then
by Canadian Bank Note after L-M stopped printing postage stamps.
In 1998 CBN printed the same design in a smaller size format
and in the same year Ashton - Potter Canada Limited printed booklets of 30.

There is a noticeable difference in the stamps, they have different perforations and the Leigh-Mardon ones have deeper/darker blues and reds compared to the CBN stamps.

But what I didn't notice was that Leigh-Mardon used half-tone
whereas Canadian Bank Note used stochastic screening in their
printing process.





Leigh-Mardon half-tone screen ******************* Canadian Bank Note stochastic screen

Nice clear explanation
well done.
Was not aware Leigh Mardon ceased production.

Thanks Rod.

I found the information regarding Leigh-Mardon on Glenn Morgan's site here:https://www.stampprinters.info/SPI_...tm#AUSTRALIA

The reason Canada Post let Leigh-Mardon bid on a contract was
because in 1993 Ashton Potter went bankrupt and Canadian Bank Note
was the sole printer.
In 1994 Ashton Potter reinvented itself as Ashton Potter (USA) Limited
and by 1995 started printing Canadian stamps again under
Ashton Potter Canada Limited.
In 2002 Lowe- Martin started printing stamps for Canada Post.
In December 2003 CP issued the last stamps printed by
Ashton Potter.

Canada Post now has 3 security printers for stamp production.
Canadian Bank Note ( who also print our banknotes) Ottawa
Lowe-Martin Ottawa
Colour Innovations Toronto

Another interest, I had thought the Eire Self Adhesives were printed by Sprintpak.

Two issues by Leigh Marden, the Singapore must have been printed at death's door in 1995.

Rod222, The LM sheet from the Singapore 95 show was actually produced after death's door had been firmly locked and the keys thrown away!

Singapore was the last ever attendance by Leigh Mardon at a philatelic exhibition, as they had already ceased stamp production by the time the show had opened, but still attended as they had paid to be there. I was also in attendance and had interesting conversations with the staff at their stand.

Note that the koala sheet exists as singles perf and imperf, plus in uncut printers press sheets of six sheets (two rows of three sheets), again perf and imperf. An error occurred on at least one uncut sheet where the bottom row of perforations goes through the eyes of the mother. GLENN

Thank you Glenn,
can understand why staff were sad at the passing of Postage Stamp printing.
It is curious how a company, in the business for so long, did not adapt to the self adhesive, one would think they had the finger on what the opposition may have been doing, or what the postal people were looking towards.

Glenn,way back in 2014 you wrote on page 4 of this thread.



I suppose that by now most if not all major stamp printers
ISP, Cartor, Ashton Potter USA, Enschede ,Bundesdruckerei ,Giesecke & Devrient,BCA etc
use stochastic screening to print stamps.
The 3 Canadian stamp printers use this process on all
Canadian stamps printed for a number of years now.

Joh. Enschedé Stamps B. V.,Netherlands has been printing the majority
of Austrian stamps for a number of years now.
One of the 2020 Christmas stamps portrays
Pieter Brueghel the Elder's Winter Landscape with a Bird Trap (1601)
Even though Enschedé probably has the capabilities for stochastic screening these stamps were done in the traditional half tone screens.

Curious as to why. Is the old method cheaper? Is production faster?
Would the stamp have looked better using stochastic screening?




Here below is what the original painting looks like.




In my opinion tiny little stamp surfaces do not lend themselves
too well for large paintings but stochastic screening would have
improved the appearance of this Austrian stamp.

Lithograving,

Is the old method cheaper?
Stochastic screening is more expensive for the printer when compared with using traditional means. This is because it involves a greater control over the proofing and the printing stages. Blankets and the press also have to be kept cleaner, so more frequent washing-down is needed. More staff time spent on a job = more cost.

Is production faster?
Production is certainly not faster than by traditional methods and, aside from the extra washing mentioned above, the press runs no faster or slower. The press itself does not care (or even know) whether it is printing from stochastic or from traditional image carriers (cylinders).

Would the stamp have looked better using stochastic screening?
Absolutely. Look at two otherwise identically printed stamps done stochastically and traditionally and there is no comparison. Stochastic wins hands-down every time, as this thread has regularly shown.