Once an industry in its own right: let­ter­press ink

You will need two small palette knives with springy blades around 150mm long, one with a round end, one a push-knife (with a flat end like a a high-class dec­or­at­ors scraper). Also a small hand-roller, say 75mm wide x 25mm dia­met­er, a flat ink slab 300 x 300mm or lar­ger, turps and clean­ing rags-or kit­chen roll. Some might prefer to work in rub­ber gloves.

Most print­ing ink comes in cans, of a size which many com­mer­cial print­ers use up in one job! Nev­er­the­less, such cans gen­er­ally have a close-fit­ting lid-don’t dam­age it! Inside a fresh can the ink is covered by an ‘air­tight’ waxed-paper or plastic disc, care­fully peel this back and skim a suit­able amount from the sur­face, using the push-knife without dig­ging down. A blob the size of half a golf-ball is suf­fi­cient for sev­er­al hun­dred cards or let­ter­heads. Smooth the air­tight disc back: be care­ful to avoid trap­ping any pock­ets of air. The air­tight disc restricts oxid­a­tion to a thin ring of ink around the wall of the can. If you’ve inher­ited a care­lessly used can you’ll waste, not only time, but more ink than you can use, in try­ing to pick out bits of oxid­ised ink ‘skin’-hard insol­uble chips-well worth avoiding.

Even in warm con­di­tions, ink needs ‘work­ing’ to make it usable. Don’t spread ink bey­ond a patch the width of your hand-roller but, with the round-end knife, pum­mel, lift, fold and beat it vig­or­ously. Fric­tion between the gran­ules of pig­ment and medi­um will warm and loosen the ink. Test occa­sion­ally by lift­ing the knife until the strand of ink con­nect­ing knife to slab breaks; each time you’ll notice the strand lengthen before break­ing. When you can draw up a 100 — 150mm strand, the ink is useable-con­sist­ency sim­il­ar to golden syr­up — how deli­ciously un-healthy!

Scrape most of the ink into a blob and push it out of the way to be your reserve. Roll your hand-roller back and forth over the remain­ing patch of ink, lift­ing the roller between strokes to ensure all of its cir­cum­fer­ence is evenly coated. Trans­fer, with the hand-roller, a coat­ing of ink to the ink-plate or disc of your press and, before clip­ping in the forme, work the press-rollers to and fro until they and the disc are evenly coated. Clip in the forme and, with grip­pers, etc. well clear of the type, work the rollers across ink disc and type forme sev­er­al times without actu­ally fully clos­ing platen to bed. Now press down fully and take a tri­al pull on the tym­pan (the card pack­ing on the platen) and exam­ine it carefully.

If the impres­sion is even, but under-impressed and under-inked, the thick­ness of a sheet of paper or card will improve it. Care­fully pos­i­tion lay-gauges and grip­pers to loc­ate the paper without hit­ting the type and try a sheet. If still under-inked, add a little more and try anoth­er pull; don’t over-ink, build up gradually.

An un-even impres­sion demands loc­al pres­sure adjust­ment; weak at the hinge end of the platen requires more tym­pan pack­ing, weak at the open end requires less. One corner weak, or heavy demands care­ful adjust­ment of the pres­sure screws behind the bed. If indi­vidu­al let­ters print too strong or too weak, check for and replace worn let­ters, plane it (again?) on a clean impos­ing sur­face and try again.

This guide kindly con­trib­uted by John R Smith of the Old Forge Press. Ori­gin­ally appeared in the news­let­ter of the Oxford Guild of Printers

Ink Additives

White Ink
White Ink (from Flickr)

Com­mer­cial print­ers used a myri­ad of addi­tion­al ingredi­ents to make a dif­fer­ence to their inks.  When print­ers were using a great mass of ink the unit price was very import­ant, and so cheap ink was com­mon.  A sur­vey of com­mer­cial print­ers showed that com­mon addi­tions at one time were —

  • French chalk
  • Par­affin wax
  • Lard
  • Coconut oil
  • Beeswax
  • Lub­ric­at­ing oil

Work was done to reduce the num­ber of addit­ives (known as dopes) to a real­ist­ic num­ber.  The list below should cov­er almost all changes needed to inks —

  • Heavy Var­nish
    will stiffen the ink and also make it dry a little quicker
  • Medi­um Varnish
    will soften the ink, use­ful for print­ing on a softer paper
  • Redu­cer (‘Num­ber 1’ from a com­mer­cial supplier)
    this will slow dry­ing but reduces pick­ing: the action of the ink pulling the sur­face of the paper away from the main body of the paper
  • Super­mat­ting
    this addit­ive will help ink to dry when over­print­ing on a sur­face that will not allow ink to be absorbed, like plastic or met­al foil
  • Redu­cer (‘Num­ber 2’ from a com­mer­cial supplier)
    This helps ink soak in to the paper

While some print­ers had a tend­ency to add dopes to every ink, the recom­mend­a­tion of the experts was clear: ink maker pro­duce inks that should work dir­ect from the can.  Seek advice from your ink man­u­fac­turer about what is best for a par­tic­u­lar job and paper.