Applying Precision Techniques

Heriot Watt (from ECP)
Heriot Watt (from ECP)

“Precision begins in the composing room” was the standard cry from the makers of composing room equipment. They claimed that without this foundation other work on precision would be wasted. A speaker at a BPMF conference – Mr. Philip J Wright of Bristol – expressed a slightly different view and I’ll summarise it here.

We do need to be precise in the composing room; but this will come to nothing if our letterpress machines are poorly-kept. It takes a lot of repeated effort to get each forme accurate for printing; but less time to get a press really accurate. Mr Wright suggested starting with the presses – and not the composing room – to get immediate results. The test was to take an expertly precise forme from another printer and use your own machine: any benefits from this effort will be lost with a poorly maintained machine, regardless of the effort invested in the forme.

So, get your machine ship-shape first.

Turning then to the composing room, we need to take a systematic approach to precision – again to secure the greatest immediate benefit.

  • Height of Materials
    While ‘type high’ means 0.918”, different elements of a forme will have slightly different heights: type in cases; type cast in-house; blocks; mountings etc. The first step here is to be able to accurately measure the heights of these things and work out the tolerances that you can work with. This might need a combination of different approaches to makeready
  • Horizontal Relationships between Materials
    This is about getting everything in the right place across the forme. Jack Deller noted that wooden reglet in a 3” square might change shape by anything up to 6pts under pressure. Lining up tables or drawing boards can be used to assure accurate positioning; but more simple approaches can give benefits: using metal or formica furniture in places of wood, for example.

Overall the approach needs to be defined by the type of work. For those using plates a great deal, better bases might be a quick and effective improvement. For those doing multi-colour work, lining up would be critical.

The overall scheme, though, must be get immediate improvements of one sort or another and use multiple, small steps to get better results.