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.