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Using display moulds for the composition caster

Started by John Cornelisse, November 13, 2021, 06:48:41 PM

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John Cornelisse

Some time ago I found a set of display moulds for the composition caster, and a set of holders.

The moulds have insets from 14 pt to 36 points. I wonder could these moulds be used for large-composition ?

Is there anybody under us, with some experience with these instruments ?

English display                                                           American display 

John Cornelisse

In the mean time, I got some additional info about it all.

My thanks  to Ludwig Mohr, for the emails he did sent to me.

The first tow holders will fit into the bridge, and at G9 the centering pin will keep the mat at the right place.

Two holes in the paper, G9, and the paper movement on hold. A wedge in place and the width of the cast can be adjusted by hand.


It's 20 years since I last operated a composition machine, but looking at your pics the second two look like 15x15 sized diecases so G8 or H8 would be the position for entering, however if I remember correctly,  locking the feed on the bridge will keep the main wedge lifted so positioning the mould open at around the 9 unit character width and difficult to get enough adjustment in the character width.
The only other way to amend the size is to manually set the transfer wedges to increase the character.
The first two pics look like they are more suited for a Supercaster but not sure as the size and centre pin positions look off-centre. The two on the right look a lot older than the one on the left so likely from a different machine model.
If they are from a supercaster I am not sure which bridge assembly the would run on.
Retired Compositor and Monotype Caster/Supercaster operator. Monotype trained  for maintenance and service.

David Bolton

The UK matrix holder on the left, with the long wooden handle, is for 1" display matrices to be cast on the composition caster. I have used this on my caster, but over 20 years ago, so can't remember how I got on with it. It would have a display mould on the caster, and it needed the slow speed gearing, and the centring pin auxiliary spring, etc. A photo of the holder is attached, showing top and bottom view.
I have another UK holder, image also attached, for American flat mats to be cast on the composition caster. My one looks the same as the final ones shown above. Again, I used this some 20 years ago, to cast 36pt Kennerley on my composition caster. One has to hold the matrix case at G8 and lock it in position by uncoupling the locking bar. I had trouble getting it locked, if I remember, as the caster tended to blow up several other pins, despite just G8 being punched, unless one was very quick in uncoupling the bar.


The matrix holder in the centre of the first two photos is a 49A holder for using American (Lanston) display matrices with English display moulds on the Composition caster (or its relatives like the Type-and-Rule caster).

The English display moulds of various sizes for the comp caster all have the cavity centered on the jet, whereas the American T and U moulds keep the left side of the mould (bottom/nick side of the type) fixed as the body size changes. Thus the Lanston matrices have two baselines that differ by about 12 points, one for sizes under 24 and one for 24 and up. You start with the 12-point cavity being centered on the jet, then the right type block moves out to allow larger bodies, until it almost gets to 12 points wider on the right (making an almost-24-point cavity). At this point (24, to be exact) you switch from T to U moulds, the left type block shifts 12 points to the left, and the right type block is where it was when you started at 12-point body size. Then the right type block moves to the right again until you reach 36 points, at which point the cavity is again centered on the jet.

The 49A holder has an adjustable position for the centering pin which has the effect of properly positioning the matrix over the English mould cavity location.

I am unsure whether this holder is made for use with an American (pointy) or English (blunt) centering pin; I am using it with an American pin which seems to bottom out properly in the pin hole of the holder, but I have also test-fitted an English pin which also seems to fit.

I think there are also height difference issues as I find when using this holder I need about 0.020" (0.5mm more or less) of shim behind the matrix. But then I have an English caster with an American bridge, here using an English mat holder for American mats and an English mould, so there are plenty of potential sources for this height difference!

This holder has a spring clip which holds it in the proper front-to-back position. There is no "hook" as on a standard diecase and the rear pin block is not used so it can be left in the O position which in turn gives easy access to the Mould Blade Abutment Screw for adjusting the quad.

The right-hand holder in the first two photos is the insert for the standard Lanston display matrix holder. It fits into a frame which in turn slides into the carrying frame like any other diecase. The front-to-back position is set by selecting the correct position on the rear pinblock (G or H, IIRC). This insert system is used to allow changing the matrix without the trouble of removing the (substitute for the) diecase. You pretty much do, however, have to remove the outer frame to adjust the Mould Blade Abutment Screw.

I have more discussion of the T and U moulds and the 49A mat holder on my blog at and

John Cornelisse

Usiing moulds with different heights:

English = .918 inch, French = .928 inch Belgium = .932 inch, Dutch - .9875 inch

This problem was solved in London UK, by placing a little plate under the two legs of the bridge, to compensate the missing height.

But this was not mentioned ever in the manuals...

Whenever you got somebody from Monotype along to adjust or repair your machines... you were never explained how to do this yourself. That knowledge was secret...

Buying a compcaster in Belgium was quite a disaster for a printer in Holland. There was only one special guy in Amsterdam with the knowledge needed. He was willing to do this, but did need a whole weekend. Started around 17:00 hours on Friday, when alle castermen left their working place. Did stay in a hotel for two nights, did change a lot of parts, whenever only a little bit worn. The next monday the machine could cast properly. And the bill was large in 5 figures...

The only changes needed were two parts: the typecarrier and the cross slide g5CC.

Dutch character do not fit inside English typecarriers, and the cross slide in Holland will limit the down stroke of the diecase.

Actually not needed at all, but that was kept secret too...

Monotype mechanical workers did not share their knowledge, you might not need them in future. When I was at Ridge Hopkin's printshop, I showed him to adjust the pump of his supercaster. He had not experienced that never before in all his years behind the machines...


The manuals however do explain the adjustnments in detail on the pages 38-41 of the English manual.

how to adjust the nuts a4A2, to control the down movement of the diecase.

If available you could use a few different bridges to adjust your machine to the type height needed. And leave the dutch typecarrier and the lower cross slide on the machine.

It might be somme difference using display moulds on the compcaster, never used them yet on my machine. Are there some differences for the depts inside the matrices ? I do not know.

John Cornelisse

In former days, moulds did change in time. When a mould was worn, you could sent it to London, and there the tops of mould side blocks and the mould blades were griinded.

When the mould was sent back to you, the type height was a bit less...

At some moment, new moulds were designed, numbered from 100.000: they were called "contant height" moulds. The side blocks and upper mould blade were made from hardend steel.

At some moment, I was offered a series of old moulds from the Westzaan museum Stichting Lettergieten... Some of them were French height moulds. Max Stiebner he asked those back, he did not like the idea, that I might discover how to used those moulds on my Dutch compcaster.

Later Garry Drayton showed me, that there were some constat height mould between them. They could be recognized with their high series number.

The later constant-height moulds have an extra plate on the wooden box.

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