Print­ers’ rollers have occu­pied the great­est print­ing minds since the ear­ly 1800s.  While the rotary let­ter­press machine should have improved pro­duc­tion speeds, their poten­tial was held back by the lack of rollers: just how could ink be trans­ferred to the forme with speed and con­sis­ten­cy?  This arti­cle looks at ear­ly rollers, com­po­si­tion rollers and rub­ber rollers.

Early Rollers

Printers' ink ball or dabber
Print­ers’ ink ball or dab­ber

When using the orig­i­nal hand press­es, print­ers used ink balls.  A wood­en han­dle and sheep­skin bag filled with horse­hair formed the ink ball, and these were used in pairs.  The inker could ‘mill’ the ink between the balls and then apply ink to the forme before print­ing.  This approach was used between in inven­tion of the press and 1790, some 340 years.

With the intro­duc­tion of the rotary press, print­ers sim­ply mod­i­fied their exist­ing tech­nol­o­gy and built wood­en rollers with a sheep­skin cov­er filled with horse­hair.  While made with some pre­ci­sion, they could not coat the type effec­tive­ly, and left a mark on the page where the stitch­ing in the sheep­skin cov­er did not trans­fer ink.

Composition Rollers

In 1818, Robert Har­rild devel­oped the first ‘com­po­si­tion roller’, made of glue (from calf­skins) and trea­cle — his devel­op­ment was based on the process used by the Stafford­shire Pot­ter­ies to add pat­terns to pot­tery.  While this mix­ture was tacky enough to car­ry and trans­fer ink, the ingre­di­ents led to an insta­bil­i­ty of the roller.  The glue gives up water in dry atmos­pheres and shrinks and cracks.  In damper con­di­tions, the glue takes up mois­ture and the roller swells.  Thomas de la Rue added glyc­erol (US: glyc­er­ine) to that orig­i­nal mix.  Glyc­erol has a ten­den­cy to absorb mois­ture from the air and this bal­anced to a degree the effects on glue to pro­duce a more sta­ble roller.  Rollers still had to be made to suit the atmos­pher­ic con­di­tions and sea­sons — so rollers were made to dif­fer­ent recipes in dif­fer­ent parts of the world, and depend­ing on whether it was sum­mer or win­ter.

Making Composition Rollers

Just as print­ers were expect­ed to make their own inks, they were also expect­ed to be able to cast their own rollers.  Press­es (like the Arab) were sup­plied with roller cores (the cen­tral met­al bar) and moulds for the com­po­si­tion.  Print­ers would rou­tine­ly melt down and re-cast com­po­si­tion rollers.  A big prob­lem was to pre­vent air bub­bles from sit­ting on the edges of the roller, and caus­ing small marks that trans­ferred to the inked forme.

Com­mer­cial mak­ers of com­po­si­tion rollers used a gatling gun to hold mul­ti­ple moulds and pour com­po­si­tion mix­ture into all of them at one time.

Using Composition Rollers

Adana rec­om­mend­ed four sets of rollers: two pairs of rollers each for sum­mer and win­ter; one for colour work (includ­ing white) and one for black.  Rollers would be used for colour first and then black.  Rollers should be care­ful­ly cleaned and cov­ered before stor­age using oil or petro­le­um jel­ly.  An appro­pri­ate mix would be 10% med­ical paraf­fin plus ‘suf­fers grease’ (an engi­neers’ jel­ly).

Composition Rollers Advantages and Disadvantages

Advantages of Composition Rollers

  • They are the cheap­est rollers to make of the major roller mate­ri­als
  • Ingre­di­ents can be var­ied to suit local con­di­tions
  • They are sup­plied soft (typ­i­cal­ly 15 — 20 shore) and this can roll ink to mul­ti­ple lev­els with­in a forme
  • They are easy to wash up
  • Com­po­si­tion rollers have a very smooth sur­face that can deliv­er a sharp appear­ance on print­ed mate­r­i­al

Disadvantages of Composition Rollers

  • They are less sta­ble than oth­er rollers in dif­fer­ent tem­per­a­tures and humid­i­ty
  • Cuts in the roller will spread and widen
  • They can­not be made to the same accu­ra­cy as oth­er rollers
  • They occa­sion­al­ly swell at the end