D

D.t. cover:
“Double-thick” describes a sheet of paper made by bonding two thicknesses of paper together resulting in an extra-stiff sheet.

Damp streaks

:Streaks caused by uneven pressing of drying during paper manufacturing.
Dampeners
:In lithography, cloth covered, parchment paper or rubber rollers that distribute the dampening to the press plate.
Dampening solution
:Water, gum buffered acid, and various types of etches used to keep the non – image areas of the plate moist, and preventing them from accepting ink, in the lithographic printing process; also called fountain solution.
Dampening rolls:
Chilled cylinders, situated ahead of the calender stacks, condensing a continuous spray of steam and transferring the moisture to the web of paper as it passes to the calenders. Also a spray of moist steam or water on the web of paper.
Dandy roll
:(1) A plain roll situated above the wet web of the paper to provide a smoothing action to the top surface of the paper as it passes under the roll. (2) A watermarking dandy roll is a roll of skeletal structure, sheathed in a wire cloth that has designs, letters or figures affixed to it. As the wet paper web passes under the turning watermark dandy the designs are impressed into the paper and a permanent watermark is left in the sheet.
Day-glo
:Trade name for inks and papers containing fluorescent pigments.
Debossing
:The process in which the image is recessed into the paper.
Decorative papers:
Papers manufactured with embossed or printed designs of some type which are used primarily for decoration such as gift wrapping paper. These papers come in a variety of weights, grades, coatings, finishes and colors.
Deckle
: On the wet end of the paper machine the straps or deckle rulers that prevent the fiber from overflowing the sides of the machine. The deckle determines how wide the paper on a particular machine will be.
Deckle edge
:Refers to the feathered edge on paper produced when fibers flow against the deckle or edge of the web. Deliberately produced for aesthetic purposes, a deckle edge is found especially on formal stationery and announcements. A deckle edge can be created by an air jet, or also by a stream of water.
Decurler
: A device on a web press or sheeter used to remove paper curl.
Decurling
:A paper decurling station on a sheeter or web press, used to remove paper curl.
Defects:
Irregularities appearing on finished paper that spoil the appearance or cause weakness in the sheet.
De-inking
:A process which removes ink, toner, coatings and most fillers from recovered paper. The environmental priority is to make this process TCF, totally chlorine free.
Delamination:
Parting of layers of a sheet of paper made on a cylinder machine.
Delivery:
Area of the originating press where the freshly printed sheets are piled as they leave the impression section.
Densimeter:
Equipment used to analyze the porosity fo a given sheet of paper.
Densitometer:
Reflection instrument measuring the density of colored ink to determine its consistency throughout a press run.
Density
:Identifies the weight of paper compared to the volume; it is directly related to the paper’s absorbency, stiffness, and opacity.
Descender
– The parts of lower case letters that extend below the baseline.
Diagonal Seams:

Seams running from the bottom corners to near the center of the throat where the envelope is glued together with the Bottom Flap.

Die cutting:
Male and female dies are used to cut out paper or board in desired shapes.
Digester:
Pressure vessel in which wood chips are cooked to separate fibers from each other and to remove detrimental particles.
Direct halftone:
Halftone for which the screen negative was made directly from the subject to be reproduced.
Dirt count:
The average amount of dirt in a specific size of paper area. Both virgin and recycled sheets have “dirt,” although recycled paper has significantly higher dirt counts. The dirt should always be small enough not to interfere with the quality of the finished printed piece.
Die
:A design, letters, or pattern cut in metal for stamping, embossing or for diecutting.
Die-cutting
:Male and female dies are used to cut out paper or board in desired shapes.
Digester
:Pressure vessel in which wood chips are cooked to separate fibers from each other and to remove detrimental particles.
Dimensional stability
:Characteristic of paper to retain its dimensions in all directions under the stress of production and adverse changes in humidity.
Dirt
:Dirt in paper consists of any imbedded foreign matter or specks, which contrast in color to the remainder of the sheet.
Dished
:Concave rather than flat pile of paper. Also refers to roll ends of paper that are not flat.
Distributor
:Company which purchases paper from mill for resale to printers and end-users. Usually a distributor has protected or franchised product lines and territories. Inventory, warehousing, distribution and transportation of product are among the many services offered to paper buyers. Also called a merchant.
Dividers
:Tabbed sheets of index or other heavy stock, used to identify and separate specific sections of a book; used in loose-leaf and bound books.
Dot
:Individual element of a halftone printing plate.
Dot etching
:Handwork on engravings and lithographic screened (halftone) negatives for correcting tonal values in either black-and-white or color work.
Dot gain:

When the dots in halftone printing become larger than desired.

Dot slurring
:Smearing or elongation at the trailing edges of halftone dots.
Dot spread
:When halftone dots print larger than they were supposed to print.
Dots, halftone
:The individual subdivisions of a printed surface created with a halftone screen.
Double burning
:Combining the images on two or more films onto a single film to create a single image.
Double calendered:
A paper run through two calenders.
Double coated:
A sheet that has been coated twice on the same side. Sometimes confused with a sheet coated on both sides.
Double printing:
Printing different negatives – line and halftone – in succession and in register on the same sheet of sensititzed metal.
Double varnish
:Two applications of press varnish.
Double-black halftone printing
:A means of extending the range of density available with printing ink by printing twice with black ink, using two specially prepared halftone negatives. Also called double-black duotone.
Double printing:
Printing different negatives – line and halftone – in succession and in register on the same sheet of sensititzed metal.
Double-deckle paper
:A paper having parallel deckle edges.
Double-dot halftone
:Two halftone negatives combined onto one printing plate, having greater tonal range than a conventional halftone negatives. One negative reproduces highlight and shadows, the other middle tones. This is not to be confused with duotone or double-black printing.
Double-thick cover stock
:A cover stock composed of two sheets of 65 lb. Cover stock laminated together.
Doubling
:(1) In printing, a press problem that generally occurs when sheets make contact with the blanket twice, once just before the impression point and the second time at the impression point, resulting in a double image. At times, with certain papers, the feeder will feed two sheets instead of one, and when pressures are extreme or out of balance, the blanket may slip at the pressure point, resulting in a slur or double image. (2) In stamping, a double impression in which the second impression or “hit” does not register perfectly over the first one.
Doughnut hickey
:A printing defect consisting of a solid printed area surrounded by an unprinted area.
Downtime
:Duration of an unscheduled stoppage of machines or equipment (printing presses, papermaking machines, typesetting equipment, etc.), usually caused by malfunction.
Drag
:Register trouble when the dot is enlarged toward the back (nongripper edge) of the sheet. See Slur.
Draw-down
:A term used to describe an ink chemist’s method of roughly determining coating or ink. The application (by a blade or a bar) of a thin film of coating or ink to a piece of paper.
Drawing paper:
Good quality, dull finished paper sufficently stable to take erasures.
Dryer (drying oven):
In printing, oven on web offset press through which the web of printed paper passes after it leaves the final printing unit. The drying process, standard when heat-set inks are used, heats the web to about 350 degress F. Either electricity dries the vehicles and air blasts drive off the volatile gases.
Drier
:Any substance used to hasten drying of ink on paper.
Driers
:Wet paper passes through these large cylindrical steam heated rolls that dry paper webs. The dry-end of the paper machine.Also known as dryer.
Drilling
:Piercing of stacks of papers in a precision manner with round hollow drills at high speeds. Loose-leaf notebook paper is an example of drilled paper.
Drop-out
: In printing, halftone with no screen dots in the highlights or background. Also, color not sensed by optical reading devices. Also, ink colors which will not image a photographic plate.
Dry back
:The color change which occurs when ink dries.
Dry-end
: On the paper machine, it is the section where the dryers, cutters, slitters and reels are located.
Dryer (drying oven)
:Oven on web offset press through which the web of printed paper passes after it leaves the final printing unit. The drying process, standard when heat-set inks are used, heats the web to about 350 degrees Fahrenheit. Either gas or electricity dries the vehicles and air blasts drive off the volatile gases.
Drying time
:The time it takes for an ink to become rub- or tack-free.
Dummy
:Page or set of pages assembled in the exact position, form and style desired for the finished piece of printed work. Used as a model or sample for the printer.
Duotone
:Two-color halftone reproduction from black-and-white original.
Duplex
:Paper having a different color on each side.
Dusting
:The accumulation of loose particles from the paper on the nonimage areas of the blanket. Particles are of very small size.
Dye
:An ink colorant that is soluble in vehicle or solvent.
Dye transfer
:Similar in appearance to a color photograph but different in the important respect that it is produced from a transparency by printing continuous tones of color dyes.
Dylux:
A stable print specially sensitized on two-sided papers for proofing.