The Printing Forme for Letterpress Production.


The Chase
A rectangular metal frame (usually cast iron) called a chase was the basis of the printing forme for many years. The type was placed on a flat surface called a metal compositor’s stone and locked into position.
This metal frame is used to hold type in place while printing, usually on a platen press or flat bed press.
Type and blocks are locked up towards the centre of the chase using furniture to position it and quoins to apply pressure against the type matter.
Lock up was done on a composing stone to ensure that type was level. Before the quoins are tightened a wood planer is tapped gently on the type surface using a wooden printer’s mallet to confirm the feet are flush against the stone and completely level.
The size of a chase matches a specific press. The measurements, in inches, of the inside of the chase are also used to describe the press size.
Some chases, especially large ones, have handles at the top to assist the printer in both transporting and placing the chase in position on the press.
Chases can also be useful with flatbed presses for a variety of situations. Composition of complex forms can be created on a composing stone in a large chase, then brought to the press before printing.
The photograph above shows the bottom right hand corner of a chase into which type – in this case lines of type (sometimes called slugs) – spaced with various pieces of “furniture” have been locked up..
Furniture was normally wood but sometimes strips of lead, Elrod material, Monotype supercaster material  or cornerstone.
Quoins (pronounced “coins”) were used to secure the whole assembly.
Sometimes two wooden wedges were set against each other to tighten the forme and to keep the furniture parallel to the side of the chase.
I had never seen hempel quoins (in the second picture below) until I started at The Guv in 1973. Up until then I had been using Cornerstone (British) Quoins which I considered superior.
In the picture above spring loaded quoins are being used. When a quoin key is turned in the threaded part of the quoin (the circle with the square recess) the two sections spread to apply pressure to the furniture to keep the whole assembly firm and secure.
Turning the quoin key in the opposite direction slackens the pressure off and releases the furniture and type.
Once the type was arranged in its final printing position, the  quoins were tightened up and the forme “planed down”. The whole chase, complete with its contents, was then transferred to the printing press.
In this form the chase and contents were called a “printing forme”.


About Derwombat

My name is Rod Parham, Hot Metal Compositor. I was born in Adelaide, South Australia in 1947. Single with two children and a grandson. I Love History, Movies and Words.

2 Responses

Comments are closed.