LITHOGRAPHY
Lithography was invented in 1798 by a man called Alois Senfelder. He was trying to find an inexpensive method of publishing his plays. He discovered that if he drew a design on a marble gravestone in wax crayons, then wet the stone and applied a greasy ink, the ink only stuck to the waxed areas of the stone. The image could then be copied onto a sheet of paper pressed against the stone. This method was used by the famous French Artist Toulouse Lautrec to create his famous series of posters of the theatres and restaurants of Paris. 

The process evolved slowly through the early part of the twentieth century, but as photographic processes grew more sophisticated, it became possible to create flexible metal plates coated with special photo-sensitive coatings. If a photographic stencil was made by photographing a page containing text and pictures, it could be laid on the plate and exposed to a bright light source. After developing, the exposed parts of the plate would then attract the greasy ink and the unexposed parts of the plate would attract water. The resultant "inky" image could then be transferred onto the paper.

Commonly Used Terms in the Printing World

Accordion fold: Bindery term, two or more parallel folds which open like an accordion.

Alteration: Change in copy of specifications after production has begun.

Back up: Printing the second side of a sheet already printed on one side.

Basis weight: Weight in pounds of a ream of paper cut to the basic size for its grade.

Bind: To fasten sheets or signatures with wire, thread, glue. or by other means.

Bindery: The finishing department of a print shop or firm specializing in finishing printed products.

Bleed: Printing that goes to the edge of the sheet after trimming.

Blind embossing: An image pressed into a sheet without ink or foil.

Bond paper: Strong durable paper grade used for letterheads and business forms.

Butt: Joining images without overlapping.

Carbonless: Pressure sensitive writing paper that does not use carbon.

Camera-ready copy: Print ready mechanical art.

Cast coated: Coated paper with a high gloss reflective finish.

Coated paper: A clay coated printing paper with a smooth finish.

Collate: A finishing term for gathering paper in a precise order.

Color separations: The process of preparing artwork, photographs, transparencies, or computer generated art for printing by separating into the four primary printing colors.

Comb bind: To plastic comb bind by inserting the comb into punched holes.

Contrast: The tonal change in color from light to dark.

Copy: All furnished material or disc used in the production of a printed product.

Crash number: Numbering paper by pressing an image on the first sheet which is transferred to all parts of the printed set.

Crimping: Puncture marks holding business forms together.

Crop: To cut off parts of a picture or image.

Crop marks: Printed lines showing where to trim a printed sheet.

Cyan: One of four standard process colors. The blue color.

Die: Metal rule or imaged block used to cut or place an image on paper in the finishing process.

Die cutting: Curing images in or out of paper.

Dummy: A rough layout of a printed piece showing position and finished size.

Duotone: A halftone picture made up of two printed colors.

Emboss: Pressing an image into paper so that it will create a raised relief.

Flood: To cover a printed page with ink, varnish, or plastic coating.

Foil: A metallic or pigmented coating on plastic sheets or rolls used in foil stamping and foil embossing.

Foil emboss: Foil stamping and embossing a image on paper with a die.

Foil stamping: Using a die to place a metallic or pigmented image on paper.

4-color-process: The process of combining four basic colors to create a printed color picture or colors composed from the basic four colors.

Gang: Getting the most out of a printing press by using the maximum sheet size to print multiple images or jobs on the same sheet. A way to save money.

Ghosting: A faint printed image that appears on a printed sheet where it was not intended. More often than not this problem is a function of graphical design. It is hard to tell when or where ghosting will occur. Sometimes you can see the problem developing immediately after printing the sheet, other times the problem occurs while drying. However the problem occurs it is costly to fix, if it can be fixed. Occasionally it can be eliminated by changing the color sequence, the inks, the paper, changing to a press with a drier, printing the problem area in a separate pass through the press or changing the racking (reducing the number of sheets on the drying racks). Since it is a function of graphical design, the buyer pays for the increased cost.

Grippers: The metal fingers on a printing press that hold the paper as it passes through the press.

Hairline: A very thin line or gap about the width of a hair or 1/100 inch.

Halftone: Converting a continuous tone to dots for printing.

Hard copy: The output of a computer printer, or typed text sent for typesetting.

Image area: Portion of paper on which ink can appear.

Impression: Putting an image on paper.

Indicia: Postal information place on a printed product.

Ink fountain: The reservoir on a printing press that hold the ink.

Knock out: To mask out an image.

Laid finish: Simulating the surface of handmade paper.

Laminate: To cover with film, to bond or glue one surface to another.

Line copy: High contrast copy not requiring a halftone.

Lines per inch: The number of rows of dots per inch in a halftone.

Magenta: Process red, one of the basic colors in process color.

Makeready: All the activities required to prepare a press for printing.

Matchprint: Trade name for 3M integral color proof.

Matte finish: Dull paper or ink finish.

Moiré: Occurs when screen angles are wrong causing odd patterns in photographs.

Negative: The image on film that makes the white areas of originals black and black areas white.

Offsetting: Using an intermediate surface used to transfer ink. Also, an unpleasant happening when the images of freshly printed sheets transfer images to each other.

Offset paper: Term for uncoated book paper.

Opacity: The amount of show-through on a printed sheet. The more opacity or the thicker the paper the less show-through. (The thicker/heavier the paper the higher the cost.)

Outline halftone: Removing the background of a picture or silhouetting an image in a picture.

Overrun or overs: Copies printed in excess of the specified quantity. (Printing trade terms allow for + - 10 % to represent a completed order.)

Page count: Total number of pages in a book including blanks.

Perfect bind: A type of binding that glues the edge of sheets to a cover like a telephone book, Microsoft software manual, or Country Living Magazine.

PMS: The abbreviated name of the Pantone Color Matching System.

PostScript: The computer language most recognized by printing devices.

Process blue: The blue or cyan color in process printing.

Process colors: Cyan (blue), magenta (process red), yellow (process yellow), black (process black).

Ream: Five hundred sheets of paper.

Register: To position print in the proper position in relation to the edge of the sheet and to other printing on the same sheet.

Register marks: Cross-hair lines or marks on film, plates, and paper that guide strippers, platemakers, pressmen, and bindery personnel in processing a print order from start to finish.

Reverse: The opposite of what you see. Printing the background of an image. For example; type your name on a piece of paper. The reverse of this would be a black piece of paper with a white name.

Saddle stitch: Binding a booklet or magazine with staples in the seam where it folds.

Scanner: Device used to make color separations, halftones, duo tones and tri tones. Also a device used to scan art, pictures or drawings in desktop publishing.

Score: A crease put on paper to help it fold better.

Screen angles: Frequently a desktop publishers nightmare. The angles at which halftone, duo tones, tri tones, and color separation printing films are placed to make them look right.

Self-cover: Using the same paper as the text for the cover.

Side guide: The mechanical register unit on a printing press that positions a sheet from the side.

Side stitch: Binding by stapling along one side of a sheet.

Signature: A sheet of printed pages which when folded become a part of a book or publication.

Skid: A pallet used for a pile of cut sheets.

Specifications: A precise description of a print order.

Spine: The binding edge of a book or publication.

Spot varnish: Varnish used to highlight a specific part of the printed sheet.

Stamping: Term for foil stamping.

Stat: Term for inexpensive print of line copy or halftone.

Step-and-repeat: A procedure for placing the same image on plates in multiple places.

Stock: The material to be printed.

Stripping: The positioning of film on a flat prior to platemaking.

Text paper: Grades of uncoated paper with textured surfaces.

Tints: A shade of a single color or combined colors.

Transparency: A positive photographic slide on film allowing light to pass through.

Trapping: The ability to print one ink over the other.

Trim marks: Similar to crop or register marks. These marks show where to trim the printed sheet.

Trim size: The final size of one printed image after the last trim is made.

Under-run: Production of fewer copies than ordered. See over run.

Up: Printing two or three up means printing multiple copies of the same image on the same sheet.

UV coating: Liquid laminate bonded and cured with ultraviolet light. Environmentally friendly.

Varnish: A clear liquid applied to printed surfaces for looks and protection. (UV coating looks better.)

Wash-up: Removing printing ink from a press, washing the rollers and blanket. Certain ink colors require multiple wash-ups to avoid ink and chemical contamination.

Waste: A term for planned spoilage.

Watermark: A distinctive design created in paper at the time of manufacture that can be easily seen by holding the paper up to a light.

Web press: The name of a type of presses that print from rolls of paper.

Wire O: A bindery trade name for mechanical binding using double loops of wire through a hole.

Wire-O binding: A method of wire binding books along the binding edge that will allow the book to lay flat using double loops. See Wire O.

Work and tumble: Printing one side of a sheet and turning it over from the gripper to the tail to print the second side using the same side guide and plate for the second side.

Work and turn: Printing one side of a sheet and turning it over from left to right using the same side guides and plate for the second side.

Wove paper: A paper having a uniform unlined surface with a smooth finish.