Saddle wire
In binding, to fasten a booklet by wiring it through the middle fold of the sheets.

Score / Scoring
The process, as well as the resulting line or crease mechanically impressed in the paper, to facilitate folding while guarding against cracking of paper and board. The score should run parallel to the paper grain and be folded with the scored side on the outside. Scoring is essential when heavyweight papers are to be folded across the grain. Thick papers require wider scores.

Screen
The ruling used to determine the dots per unit area in developing tonal values in the printed piece. Screens from which letterpress halftones of photographs are made range from 60 lines-per-inch for printing on newsprint, to 150 lines for printing on coated paper. Offset halftones for printing on most surfaces range from 133 lines to 200 lines.

Screen angles
In color reproduction, angles at which the halftone screens are placed with relation to one another, to avoid undesirable moiré patterns. A set of angles often used is: black 45, Magenta 75, yellow 90, cyan 105.

Screen process printing
This printing process uses a screen of fine-mesh silk (thus the common name, silk screen printing) tightly stretched across a frame. A squeegee drawn across the screen forces ink through the open image areas, which are cut out by hand using lacquered tissue prior to its adherence to the silk. Special photographic negatives are adhered to the screen when faithful reproduction of intricate designs is sought.

Screen ruling
The number of lines or dots per inch on a halftone screen.

Screentone
A halftone film having a uniform dot size over its area, and rated by its approximate printing dot size value, such as 20%, 50%, etc. Also called screen tint.

Screening
Converting a continuous gray-scale image into dot patterns by using a halftone screen or a screen tint. In offset lithography, the screen is a glass or film with cross-ruled opaque lines or vignetted dots used to reproduce continuous tone artwork such as photographs. To create a halftone, an image is shot through the mesh screen to break it into tiny dots. The closer the line screen, the smaller the dots and the more dots per inch and, hence, the finer and crisper the printed image. Less absorbent papers reduce the spread of ink dots and, therefore, a finer line screen can be used.

Scrolls
Long sheets of paper, papyrus or parchment that can be rolled for storage.

Scuffing
Also see rub-off. The disrupted appearance of an ink film as a result of abrasion to either the wet or dry ink film.

Scumming
Scumming occurs when ink starts to appear on the non-image areas of a press plate. This condition arises for a variety of reasons, basically due to spots or areas not remaining desensitized, and will most likely require that plates be changed.

Seasoning
Process of allowing paper to adjust to atmospheric conditions of the plant in which it will be used.

Secondary fiber
A term used for wastepaper. Also referred to as paper stock.

Self cover
A booklet covered with the same paper that is used for the inside text pages.

Separation negative
One of the images of a color set.

Serif
Short cross line at the ends of the stroke of a Roman letter.

Set-off
The undesirable transfer of ink from freshly printed sheets of paper to another. Also called off-set.

Sewn book
A popular style of bookbinding in which the signatures are gathered in sequence and then sewn individually in 8s, 16s or 32s. The sewing threads are visible at the center of each signature.

Shade
The hue and depth of a particular color within the same color family, e.g., the many shades of blue.

Shadow
The darkest parts in a photograph, represented in a halftone by the largest dots.

Sharpen
To decrease in color strength, as when halftone dots become smaller. Opposite of dot spread or dot gain.

Sharpness
A photographic term for perfectly defined detail in an original, negative and reproduction.

Sheet
Term that may be applied to a single sheet, a grade of paper or a description of paper, e.g., coated, uncoated, offset, letterpress, etc.

Sheet delamination
Directly related to poor surface strength in that, if the sheet has poor surface strength, delamination will occur in the printing process. Sheet delamination could also create a problem of a blanket smash. If the delamination is large enough and thick enough, as the press continues to run, it will create a depression in the blanket so that when the delamination buildup is removed from the blanket, the depression will remain - rendering the blanket unusable. These defects pertain to both sheet-fed and web-fed equipment.

Sheet-fed press
A press that prints single cut sheets of paper, rather than a continuous roll or web of paper. Because sheet-fed presses print one page at a time, they are better suited for shorter runs.

Sheetwise
Also called work-and-back, this is a method of printing different pages - or two different forms - on the front and back sides of a large sheet of paper.

Sheffield
A test to measure the smoothness of paper by measuring the rate of airflow over the surface of the sheet.

Sheridan saddle stitcher-trimmer
A machine used to gather, cover, stitch and trim saddle stitched books.

Short-grained paper
Paper in which the predominant fiber orientation is parallel to the shortest sheet dimension.

Show-through
In printing, the undesirable condition in which the printing on the reverse side of a sheet can be seen through the sheet under normal lighting conditions. The more opaque a sheet, the less the show-through.

Shrinkage
Decrease in the dimensions of a sheet of paper, or loss incurred in weight between the amount of pulp used and paper produced.

Sidestitch
A method of binding in which the folded signatures or cut sheets are stitched with wire along and through the side, close to the gutter margin; pages cannot be fully opened to a flat position. Also called side wire.

Signature
Section of book obtained by folding a single sheet of printed paper in 8, 12, 16 or 32 pages.

Silhouette
Halftones from which the screen around any part of the image has been removed.

Signature
The term used for a large printed sheet or form after it has been folded and trimmed down to page size.

Silk screen
Also known as screen printing, this printing method forces ink through a porous screen, such as nylon, directly onto the paper or other material. An emulsion or stencil is used to block out the non-printing areas of the screen so that only type or image appears.

Sizing
The property of paper that relates to its resistance to water, other liquids or vapors. Sizing ingredients, such as starch and latex, are added to pulp before it is formed into paper or applied to the surface of the paper after it has dried. Sizing serves as a glue to keep the paper fibers tightly woven and in place so the sheet will not pick on press.

Skid
A wooden platform used to stack papers that are not packed in cartons. For large jobs, printers generally prefer receiving stock on skids.

Slack size
A paper that is slightly sized and, therefore, will be somewhat water resistant.

Slip-sheeting
Placing pieces of paper between folded sections prior to trimming four sides, to separate completed books.

Slitter
A sharp disk that cuts a paper into pre-determined widths.

Slitting
Cutting printed sheets into two or more sections by means of cutting wheels on a folder.

Slur-gauge (The GATF Slur Gauge)
A combination dot gain and slur indicator supplied in positive or negative form. It is a quality control device that shows, at a glance, dot gain or dot loss. It also demonstrates whether the gain or the loss occurs in contacting, platemaking, proofing or on the press.

Slurring
Slurring is the smearing or elongation of halftone dots or type and line images at their trailing edges and is usually caused by running too much ink. Check portions of the color bar, which will indicate if slurring is occurring.

Slurry
The mixture of pulp and water that is poured onto the forming wire of the papermaking machine. Slurry is 99% water.

Smashed or weak blanket
An area of a blanket that is no longer firm and resilient, and that gives a light impression in the center of a well-printed area. Usually caused by physical damage to the blanket at impression.

Smashing (nipping, compressing)
The binding operation following sewing in which the folded and sewn sheets are compressed to tighten the fold, making it free of air and making the front and back of the sheets the same thickness.

Smearing
A press condition in which the impression is slurred and unclear because too much ink was used, or sheets were handled or rubbed before the ink was dry.

Smooth finish
Text and cover grades that are highly calendered are called smooth finish papers. A smooth finish creates a hard, uniform surface that provides strong ink holdout and crisp dot resolution.

Smoothing press
Prior to reaching the driers, the paper web is smoothed, if necessary, by two rolls working together.

Smoothness
The even and consistent continuity, i.e., uniformity, of a paper's surface. Sheets that are flat and even provide better ink dot formation and sharper images. The flatness of a sheet of paper generally determines the crispness of the image printed upon it.

Smyth sewing
A method of fastening side-by-side signatures so that each is linked with thread to its neighbor, as well as saddlesewn through its own centerfold. Smyth-sewn books open flat. The stitching is on the back of the fold.

Soft ink
A term that describes the consistency of lithographic inks.

Softwood pulp
Pulp made from coniferous trees such as pine and fir. Typically, paper is made from a blend of softwood and hardwood pulp. Softwoods provide long fibers for strength and hardwoods have shorter fibers that contribute to smoothness and bulk.

Solid
An area completely covered with ink, or the use of 100% of a given color. In composition, type set without space (leading) between the lines.

Spacing
Intervals between lines of type.

Spec'd (specified)
Spec'd copy gives details of items such as paper, bindery techniques, type, etc., which have been determined for a given job.

Specialty papers or boards
Paper or board that is manufactured, or subsequently converted, for a specific use. These grades usually cannot be used for anything other than their intended special purpose.

Specifier
The designer or printing production worker who determines the types of paper to be used under various circumstances.

Specifying paper
The process of choosing the right paper for a specific printing job. Designers and printers typically base this on individual design, printing, handling and budget requirements.

Spectrum
The complete range of colors in the rainbow, from short wavelengths (blue) to long wavelengths (red).

Spine
Backbone of a book.

Spiral binding
Wires in a spiral form inserted through specially punched holes along the binding edge.

Split fountain
A technique for simultaneously printing two colors from the same ink fountain.

Split seal gum (envelopes)
Gum pattern on seal flap when envelopes are to be used on automated inserting equipment. Gum is broken where flap covers envelope seams. Prevents flap from sticking to the back panel during storage in humid conditions.

Spot
Smallest visible point that can be displayed or printed. The smallest diameter of light that a scanner can detect, or an imagesetter or printer can image. Spot should not be confused with dot.

Spot varnish
Press varnish applied to a portion of the sheet, as opposed to an overall application of the varnish.

Spotting out
Fine opaquing such as in removing pinholes or other small transparent defects in a negative. Also called opaquing.

Spray powder
A powder used at press to prevent set-off (off-set) of wet ink; also called anti-off-set spray.

Square halftone (square-finish halftone)
A halftone whose four sides are straight and perpendicular to one another.

Square sheet
A sheet that is equally strong and tear resistant with and against the grain.

Stabilize
A term used to describe paper that has been seasoned so that the moisture content is the same as the air surrounding it.

Stamping
Pressing a design onto a book cover using metal foil, colored foil or ink; applied with metal dies.

Standards (paper)
Terms used to indicate the manufactured specifications of a paper. Includes color, basis weight, sheet dimensions and grain direction.

Starch
Material used as a sizing agent for paper. Usually made from corn.

Static neutralizer
In printing presses, an attachment designed to remove the static electricity from the paper to avoid ink set-off and trouble with feeding the paper.

Standard substance weights-wove (envelopes)
16 lb.: Used for overseas airmail envelopes.
20 lb.: Used for commercial envelopes where strength and opacity is not a factor.
24 lb.: Workhorse of envelope papers; used for most open-side official and commercial envelopes.
28 lb.: Used for most open-side and catalog envelopes, and large (i.e., 11, 12 and 14) size commercial envelopes.
32 lb.: Used for heavy-duty and clasp envelopes.
40 lb.: Used for large envelopes, heavy-duty envelopes or envelopes used for storage and frequent reference.

Stencil
A sheet of plastic, cardboard, metal or paper in which a desired letter or design has been cut out so that ink or paint applied to the sheet will reproduce on the surface beneath.

Steel engraving
An engraved plate used in relief printing.

Step-and-repeat
Technique of affixing multiple images on a film or plate to extremely close tolerances.

Stepover / Step-up
In multiple imposition on a lithographic press plate, the procedure of repeating the exposure of a flat by stepping it along the gripper edge. Also side-by-side exposure.

Stiff
An ink with too much body.

Stiffness
Property of paper and paperboard to resist bending.

Stitched book
A popular method of sewing the signatures of a book together by stitching all the sheets at one time, either through the center of the inserted sheets or side-stitched from front to back. A very strong style of binding, but not flexible as compared with sewing.

Stitching
Use of wire fastenings as a permanent fastening for continuous forms.

Stochastic printing
Stochastic printing uses a special screening technology to make images almost continuous tone and look more like photographs than printing. Normally in printing, the printer takes a finite number of dots and varies their size in order to create the illusion of images. In stochastic printing, all the dots are the same size (very, very tiny), but the number of dots used is increased significantly.

Stochastic screening
A digital screening process that converts images into very small dots (14-40 microns) of equal size and variable spacing. Second order screened images have variable size dots and variable spacing. Also called Frequency Modulated (FM) screening. Holding registration on press is harder with stochastic screens, but the resulting color is often richer.

Stock
General term with many meanings. (1) Paper or board that is on hand in inventory. (2) Paper or board that has been designated for a particular use and awaits the printing or converting process. (3) Pulp that has been processed to a state where dilution is the only step necessary for it to be made into paper or board. (4) At any stage in manufacture wet pulp is referred to as stock. (5) Wastepaper.

Stock item
Paper that is manufactured and kept in inventory.

Stock sizes
Standard sizes of paper or board.

Stock weights
Weights of papers stocked by mills and merchants.

Stocking items
Papers manufactured in popular sizes, weights, colors, etc. on a regular basis to maintain adequately stocked inventories in mill warehouses.

Stocking merchant
Paper distributor that stocks enough paper in their own warehouse facilities to immediately fill anticipated orders in the market. This eliminates the delay of ordering from the paper manufacturer, taking delivery and delivering to the customer.

Stopping out
An application of opaque to photographic negatives. Also, the application of special lacquer to protect areas in positives in dot etching, staging of halftone plates during relief etching or protecting certain areas of deep-etched plates so that no ink will be deposited on the protected areas.

Stream feeder
A type of press feeder that keeps several sheets of paper, overlapping each other, moving toward the grippers.

Stretch
Describes the "give" of a sheet of paper when it is subjected to tensile pressure.

Stretch resistance
Stretch properties are essential for paper to fold well and to resist stress in use. Stretch resistance is measured on tensile testing instruments.

Strike-in
Penetration of printing ink into a sheet of paper.

Strike-through
Penetration of printing ink through a sheet of paper.

String-and-button (envelopes)
An envelope made with two reinforced paper buttons, one on the flap and the other on the back of the envelope. To close, a string that is locked under the flap button is wound alternately around the two buttons. Used mostly in interoffice and other reusable envelopes.

Strip-and-seal (envelopes)
Type of pressure sensitive adhesive applied to the envelope flap and covered with a protective strip until the envelope is ready to be sealed.

Stripping
In offset, negatives are properly positioned on a masking sheet (goldenrod masking paper). In photoengraving, film containing the photographic image from the wet-plate is moved and turned.

Substance weight (also see basis weight)
Weight measure in pounds, of a ream (500 sheets) of paper in its basic size. Different grades of paper are sold in different basic sizes. Therefore, basic weights of different grades of paper cannot be compared directly, e.g., a 24 lb. white wove is comparable to a 60 lb. offset, not to a 24 lb. offset.

Subtractive primaries
Yellow, magenta and cyan - the hues used for process color printing inks.

Sulphate
Alkaline process of cooking pulp also known as the kraft process. Wood chips are cooked to a high brightness without fiber degradation in a substance of sodium sulfate and sodium sulfide.

Supercalender
A stack of alternating steel and fiber covered rolls at the end of the paper machine that heat and iron paper to provide a high-gloss finish.

Supercalendering
Alternating rolls of highly polished steel and compressed cotton in a stack. During the process the paper is subjected to the heated steel rolls and "ironed" by the compressed cotton rolls. It imparts a high-gloss finish to the paper. Supercalender stacks are not an inherent part of the paper machine, whereas the calender rolls are.

Surface plate
One of the two basic types of lithographic press plates. A colloid image is formed on the light-sensitized metal plate by the action of actinic light passing through photographic negatives.

Surface sized
Term applied to paper that has been sized by applying a sizing agent when the web of paper is partially dry. Purpose is to increase resistance to ink penetration.

Surface texture
The texture on the surface of the paper, such as smooth, matte, laid, cockle, linen, wove, etc.

Surprint
An additional printing over the design areas of previously printed matter. Its equivalent in stripping uses overlay positive films on negatives, or photographic contact procedures to produce such overprints as "Sale," "$1.98," "Sample," etc. Also called overprint.

Swatchbook
Same as sample book. A grouping of papers, usually in bound form, that displays the weights, colors, finishes and other particulars of a collection of papers to aid in the selection of grades.