In papermaking, the cylinder that creates a laid, wove, or watermark effect.
De-Inking
Process consisting of separating the ink from the fibers. This process is only carried out when the end-product needs it, such as for printing and writing paper, for magazines, for cellulose wool, and for certain types of packaging. De-inking consists of separating the ink particles mechanically and through the use of soap to create bubbles. While fixing themselves on particles of ink, these bubbles float up to the surface of the vat and are then recovered. According to their composition, the "sludge" derived from de-inking can be reused in the agriculture and forest management, as soil amendment or to find other applications.
Deckle
The width of the wet sheet as it comes off the wire of a paper machine.
Deckle Edge
The feathered edge of a sheet produced by blowing streams of air or water at the edges of the web (roll) as it is being manufactured.
Degreasing
Removing dirt and oils from the stretched screen before applying the stencil to insure adhesion to the screen surface.
Delamination
The internal splitting of paper in the printing nip which occurs most on the heat-set web offset blanket-to-blanket presses. It is due to a weakness in the body paper or high ink tack. Separation of the ply bond of boards or laminated paper materials.
Densitometer
Photoelectric device that measures either the reflected or transmitted density of photographic film or printed colour.
Density
Ratio of the weight of paper to the volume, i.e. high-density paper has a high weight to volume ratio.
Diameter
The outside diameter of the roll.
Diazo
A photosensitive chemical added to emulsion used in making screens (stencil).
Dimensional Stability
The ability to maintain size. The resistance of paper to dimensional change with change in moisture content or relative humidity.
Dioxins
Dioxins are organochlorines, unwanted and toxic by-products formed in papermaking when chlorine from bleaching combines with molecules in wood. They are also formed during the manufacture of PVC. Dioxins have been linked with hormone disruption and an increased risk of cancer. Both the paper and plastics industries have made major reductions to the release of dioxins in recent years.
DIP
De-inked pulp. Pulp consisting of fibre from paper previously printed, which has had the ink removed.
Direct Emulsion
A liquid photo-polymer emulsion used as a screen printing stencil which is coated onto a stretched screen, dried, exposed through a film positive to actinic and developed.
Dispersion
The breaking up of a particle aggregate into separate particles without changing the particle size.
Distributor
A user type that acts in both the buyer and seller roles.
Dithering
Alternating the values of adjacent dots or pixels to create the effect of intermediate values or colours.
DOD
Drop on Demand. An inkjet technology describing ink ejected from an orifice drop by drop as it is required to form the image. There are two technologies Thermal Bubble Jet and Piezo-electric (q.v.).
Dot Gain
A printing problem where dots print larger than desired, creating darker tones or colour imbalances.
Dots Per Inch (DPI)
A reference for the resolution of a printed or screened image. Higher numbers mean higher resolution or more dots composing an image.
DPI
Dots Per Inch. A measure of the resolution of a display or output device. DPI is a strong, but not the only determinant of image quality.
Drivers
Software that instructs the computer on how to talk with its specific peripheral components, such as scanners, drivers and printers.
Dry-End
That part of the paper machine where the paper is dried, calendered, and reeled.
Dummy
An exact, handmade format sample created with blank paper to show the desired size, shape, weight and general appearance of a project prior to production.
Dye Based Inks
A very common ink type in which the colorant exists as individual dissolved molecules rather than solid particles. Dyes may be dissolved in water or solvents, and can form bright colours. However, they are very much coating dependent, usually with low UV stability and slower dry times on coated substrates.
