Hi Paul – (my first sentence was just an… excuse? to write the post – and, yes, I have tried searching the GMB both this way and that without finding very much. Unfortunately, these days the word “etching” seems to include all kinds of ways to obtain matt surfaces, sandblasting included.)
Trying to answer your questions in order of appearance:
Quite right, pantographs are for copying and/or scaling (some pantographs cannot change scale).
You write: on glass, that process can be created (…) more easily (…)
I would like to know more about that – remember pantographs (as we know them, at the museum) were used “everywhere” (in Swe glassworks) by the end of the 1800s – beginning 1900s). On the assumption they were all imported (the machines), then they were probably used in many places on the continent (and probably UK) before that.
So: what kind of machines were (at that time) able to decorate up to 24 (possibly 36) glasses at one go?
(I know sandblasting was used, but 1. it can only give matt surfaces without later polishing and 2. were there really that big “automats”?)
(the selection of cog wheels has nothing to do w the pantographs, they are for the guilloche machines – more later)
If you look at
http://bergdala-glastekniska-museum.se/eng-pantograf.html there is a picture from a book of our p used in Kosta, in the 1950ies. So yes, there is a worker operating the stylus. It takes a skilled worker (or at least one with a good memory) to follow all of the lines, short and long, without missing one.
On the page
http://bergdala-glastekniska-museum.se/eng-pantograf-skalning.html there is some text, and also a short video. The speaker text is in Swedish, and also not quite right, but is does show the mechanics. (We will make a new and better one this summer.) There is also a very short video on the blog (
https://bergdala-museum.blogspot.se/2017/09/en-torsdag-utan-besokare.html) showing our first attempt to use a pen on a paper mug – the thought being that we could let visitors “decorate your own paper mug”. (Doesn’t sound very romantic, but neither is using hydrofluoric acid…)
You mention “other(s machines) used in the mechanical acid etching”. What machines would that be?
Guilloché machines are generally much smaller than pantographs, but 1. they make other kinds of patterns and 2. they generally only take a couple of glasses at a time (we have heard of max 6, which can be correct or not)
So: I will dare to propose that pantographs are unequalled in decorating many (24) glasses at one go, AND (as they essentially are “copy machines”, ie can render any kind of pattern, including letters, small free-standing patterns) are more versatile, pattern-wise, than other machines (known to us).
Templates: yes, 95 (or so) % have patterns on both sides – if there is space there can be 2 or 3 patterns on one template.
This is getting too long already, but for a discussion about the difference between pantographs and guilloche machines, read more at
http://bergdala-glastekniska-museum.se/eng-guill-eller-panto.html )
One last question: I had the impression that Broadfield house is closed, never to be opened again?
Pls correct me… as I will be in London for a few days next week…