A composition roller is a tool used in

letterpress printing Letterpress printing is a technique of relief printing for producing many copies by repeated direct impression of an inked, raised surface against individual sheets of paper or a continuous roll of paper. A worker composes and locks movable t ...

to apply ink to a bed of type in a

printing press A printing press is a mechanical device for applying pressure to an inked surface resting upon a printing, print medium (such as paper or cloth), thereby transferring the ink. It marked a dramatic improvement on earlier printing methods in whi ...

. It consists of a cylinder made of a substance known as "roller composition" or simply "composition", a mixture of hide glue and sugar (in the form of

molasses Molasses () is a viscous byproduct, principally obtained from the refining of sugarcane or sugar beet juice into sugar. Molasses varies in the amount of sugar, the method of extraction, and the age of the plant. Sugarcane molasses is usuall ...

treacle Treacle () is any uncrystallised syrup made during the refining of sugar.Oxford Dictionary The most common forms of treacle are golden syrup, a pale variety, and black treacle, a darker variety similar to molasses. Black treacle has a distinctiv ...

), with various additives such as

glycerin Glycerol () is a simple triol compound. It is a colorless, odorless, sweet-tasting, viscous liquid. The glycerol backbone is found in lipids known as glycerides. It is also widely used as a sweetener in the food industry and as a humectant in pha ...

depending on the particular recipe. Early recipes also included

gypsum plaster Plaster is a building material used for the protective or decorative coating of walls and ceilings and for Molding (decorative), moulding and casting decorative elements. In English, "plaster" usually means a material used for the interiors of ...

and tar, though these were eventually found unnecessary. 1906 ATF composition hand roller

Before its invention, most inking of printing presses was done by manually pounding the type with

ink ball An ink ball, inking ball, or dabber is a tool used in printmaking and letterpress printing to apply ink to the plate or type to be printed. Ink balls had been used since the dawn of the printing press in the 15th century. In printmaking, they w ...

s, specially treated leather balls stuffed with wool. The difficulty and time involved in making and using ink balls led to various attempts to use cylinders, which could be rolled rather than pounded. Leather rollers (or "skin rollers") were attempted, and were used on the earliest steam-powered cylinder presses, yet these did not work as well as the ink balls, and the stitching seam would appear on the printed type. Eventually, a substance was found with the right

adhesion Adhesion is the tendency of dissimilar particles or interface (matter), surfaces to cling to one another. (Cohesion (chemistry), Cohesion refers to the tendency of similar or identical particles and surfaces to cling to one another.) The ...

and elasticity to make suitable cylindrical rollers. Composition for use in inking was developed in England in the 1810s by Robert Harrild and another individual named Forster; they first used it for making ink balls, though they soon turned to making rollers.

Bryan Donkin Bryan Donkin FRS FRAS (22 March 1768 – 27 February 1855) developed the first paper making machine and created the world's first commercial canning factory. These were the basis for large industries that continue to flourish today. Bryan D ...

was the first to apply the composition roller to a machine press. By 1826, such rollers had been introduced into the United States. To make a roller, the ingredients are melted together in a double-boiler kettle. The process is timed to avoid

candy Candy, alternatively called sweets or lollies, is a Confectionery, confection that features sugar as a principal ingredient. The category, also called ''sugar confectionery'', encompasses any sweet confection, including chocolate, chewing gum ...

ing the molasses. The mixture is cast into molds around a wooden or metal "stock" or core, which after cooling and seasoning is then hooked onto the handle or printing press. The performance of composition rollers was notoriously subject to their environmental conditions. Composition rollers tend to quickly dry out, shrink, and harden, and as a result are typically stored in sealed cabinets called "roller closets", often with a thin layer ink left on the roller as a form of protection. Glycerin, which has an affinity for moisture, was eventually added to the recipe, yet that in turn could cause trouble in warm humid weather where too much moisture would be absorbed. The mixture itself varied depending on the time of year in which they were made, with winter rollers sometimes melting in summer, and rollers made in the summer becoming brittle in winter. However, composition rollers that hardened or otherwise were unusable could be melted down and recast. By the turn of the 20th century, composition rollers were mass-manufactured by various companies, using machines that could cast several rollers at once, using a mixture containing more glycerin than molasses.

References

{{Letterpress Letterpress printing History of printing

See also

References