A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Obscene Publication Act of 1857
A law enacted in England to keep printed material that might corrupt weak minds away from the hands of those open to immoral influences, and to deny contraceptive information to the working class. Donald McGill, a well known illustrator of saucy postcards, was prosecuted under this law in 1954. His conviction caused many distributors to destroy their inventory and manufacturers to cease production of this genre out of fear of prosicution. Government agents, with the help of local watch committees, were assigned to seaside resorts in order to confiscate indecent postcards.

Octochrome
A trade name for a type of postcard distributed by the American News Company that was printed using four-color continuous tone lithography. These cards are characterized by a sharp look with hard clean colors that emphasize blues and reds. They were printed in Germany.

Offset Lithography
A printing process in which an image is transferred (offset) from one surface to another by indirect means. The general principals involved are identical to traditional metal plate lithography. The difference between them is in the manner they are printed. Various offset printing presses may have different roller systems but all share three major components; a plate cylinder that holds the printing plate, a blanket cylinder wrapped in rubber that carries the image, and the impression cylinder which applies the pressure to print the image. A processed litho-plate containing an image is mounted on a cylinder, mechanically dampened with a wetting agent, and then rolled with ink. The oily ink is repelled from the damp areas and is attracted to the image areas. A blanket cylinder is then rolled over it, picking up the image onto its soft rubber surface. Paper then passed between this blanket cylinder and the impression cylinder, which presses all three surfaces together, transferring the image to the paper. If a web press is used, additional rollers will cut the paper. By using an intermediate soft roller to transfer the image, the delicate metal litho-plate suffers less abrasion and can be used for a longer period before wearing out. The soft roller can also pick up and deposit ink better than a hard surface, creating impressions with greater fidelity. This process was discovered by accident in 1900 by Ira A. Rubel. Shortly afterwards Charles Harris invented the first Rotary Offset Press. This process was not widely used for commercial printing until the 1950’s when an easy to use, storable, photosensitive metal litho-plate was developed.

Oilochrom
A trade name used by the publisher J. Salmon on some of his artist signed cards that reproduced oil paintings. These cards closely resemble the Oilettes issued by Raphael Tuck & Sons.

Oilette
A term used by Raphael Tuck ’ Sons to refer to their postcard series that reproduced scenes copied from specially commissioned paintings rather than photographs. The first oilettes were similar in style to their early chromolithographs that captured recognizable views. The later issues were more to completely generic with an embossed textured surface added to simulate the brush strokes of paintings and are sometimes referred to as oilfasism. All oilettes were copied onto printing plates by photochemical means and printed in halftone.

Optical Blending
The process by which the eye perceives a single color that is actually a mixture of two or more different reflective colors. If Magenta is printed on a page in small dots leaving white paper showing, both will reflect back to the eye as pink. If the proper amount of yellow dots are interspersed within it, it will then appear as orange.

Optical Brighteners
Chemicals similar to dyes that absorb high energy light in the violet and ultraviolet wavelengths of the electromagnetic spectrum and reflect it back out as blue light. A surface treated with an optical brightener emits more visible light than shines on to it, making it appear brighter. This increase in blue wavelengths also creates a whitening effect by making materials look less yellow. Brighteners are used in a variety of papers including modern photo papers.

Optical Tones
Different values of gray as perceived by the eye that are created by a series of different sized markings, usually dots, of one single value. When the marks fall beneath the size where they can be perceived apart from their substrate they take on the illusion of a solid tone. By varying the proportions between the dark ink marks printed and a lighter backdrop an entire tonal range from black to white can be produced in either subtle transitions or solid hard edged shapes. Most optical tones derive from the employment of line screens in reproduction to create halftones.

Oranograph
See Uranograph

Orientalism
An exotic manner of depicting the people, culture, and land from the Levant. Orientalism was widely employed in the arts and literature in the later half of 19th century. As Islam spread beyond the Arabian peninsular so did the definition of the Orient to include all Muslim lands. The Russian seizure of Central Asia, Austria’s dominance of the Balkans, France’s move into North Africa, and the British conquest of Egypt provided easier access to these places to both European and American artists. In ever increasing efforts to generate sales, artists began to travel to Muslim lands in search of new themes. Cultural differences whether real or imagined needed to be stressed in order to present something new. In depicting a foreign culture artists also had license to paint topics that were totally unacceptable to express in a Western context. While Orientalist painting was often overtly erotic in nature, it was also used to present a more fanciful exotic setting for illustration and advertising. No one style dominated this art movement, its cohieciveness was derived from a limited geography. Orientalism has additional meanings when applied to writing or cultural studies. It can be said that the concept of Orientalism created a false image of the Muslim world in order to rationalize European exploitation. While the arts may have reinforced these ideas, they did not share the same goals; Orientalism in the arts was largely used as a marketing ploy to increase sales, and whether a falsehood or not it provided the inspiration for new types of imagery in the fine and graphic arts.

Orotone (Goldtone)
A positive photographic image on a glass plate with a metallic backing. They may have been made by contact printing one glass negative to another. The image is exposed to a photosensitive silver emulsion in a collodion or gelatin base. Afterwards the back of the glass plate is coated with a mixture of bronze (copper and zinc) in oil, to give the image a golden luminous effect. These images were sold framed due to the fragile nature of glass and the painted back that is easily scratched. This uniquely American process is sometimes called Curt-tone after its first practitioner Edward S. Curtis.

Orthochromatic
A film or photo paper that is sensitive to all wavelengths of the visual spectrum except red. This allows it to be processed under red safety lights despite its fast speed. Today it is sometimes used in graphic work with process cameras. Invented by Herman Vogel in 1873.

Overprint
The printing of information or an image onto a card at a later date that was never part of its original design. Overprints were sometimes used with or without strikethroughs to make corrections in a cards title. This may be needed to correct a mistake in printing or to recognize a change in place name. Most often overprints were used to add advertising or holiday greetings to a card. Instead of going through the expense of designing a whole new card for a product, a card with an image already on it would be found and a small advertisement would be place on its front or back (not to be confused with stock cards). Overprints were usually in one color so they were easy to print on a hand press without fears of mis-registration. While some advertisers found imagery to match their product, other printed over cards in an arbitrary fashion.