Skip Ribbon Commands
Skip to main content


Paper & Pulp Dictionary Glossary "I"

Copypaper logo

 Definitions for commonly used terms, words and phrases used in the pulp and paper trade



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


The absorption of liquid by a fiber without a corresponding increase in volume.
Process of treating a sheet of paper with a chemical or wax so that the treatment penetrates into the paper.
Impression Cylinder
The cylinder or flat bed of a printing press that holds paper while an inked image from the blanket is pressed upon it.
Impression Watermark
Semi-genuine watermark made in the paper machine press section using engraved rolls while the web is still wet.
Index Paper
A stiff, inexpensive paper with a smooth finish. The high bulk but low weight of this paper makes it a popular choice for business reply cards.
Industrial Papers
A very general term, which is used to indicate papers manufactured for industrial uses as opposed to cultural purposes. Thus, building papers, insulating papers, wrapping papers, packaging papers, etc. would be considered industrial papers.
Infra Red Drying
Electric or gas infra red dryers used to initially achieve immobilization of the fluid coating and commence the drying process.
Printing inks are made up of pigment, pigment carrier and additives formulated to reduce smudging, picking and other printing problems associated with ink. The choice of ink depends on the type of paper and printing process.
Ink Absorption
A paper's capacity to accept or absorb ink.
Ink Coverage
The portion of the total surface area of the paper which is covered by ink. The portion of the coverage usually is expressed in terms of percent of ink coverage.
Ink Holdout
The way the ink pigment sits on the surface of the paper. Strong ink holdout results in a sharp, bright image.
Ink Jet Printing
Printing process of an image or text by small ink particles projected onto the paper surface.
Ink Tack
The body or cohesiveness of ink. The measure of tack as the force required to split an ink film.
Insect Resistant
Paper treated with insecticide compounds to make it resistant to insect attack.
Insider Liner
The liner bonded to the medium at the single facer. Called inside liner because it is the inside facing of a corrugated box. Also called the single face liner.
Insulating Board
A type of board composed of some fibrous material, such as wood or other vegetable fiber, sized throughout, and felted or pressed together in such a way as to contain a large quantity of entrapped or "dead" air. It is made either by cementing together several thin layers or forming a non-laminated layer of the required thickness. It is used in plain or decorative finishes for interior walls and ceilings in thickness of 0.5 and 1 inch (in some cases up to 3 inches) and also as a water-repellent finish for house sheathing. Desirable properties are low thermal conductivity, moisture resistance, fire resistance, permanency, vermin and insect resistance, and structural strength. No single material combines all these properties but all should be permanent and should be treated to resist moisture absorption.
A method of printing in which an image or letter is cut into the surface of wood or metal, creating tiny wells. Printing ink sits in these wells, and the paper is pressed onto the plate and into the wells, picking up the ink.
1. Gravure is considered an intaglio printing process.
2. In papermaking, watermarking from countersunk depressions in the dandy roll  to provide a whiter or denser design instead of increased transparency.
Integrated mill
A mill which starts with logs or wood chips and first produces wood pulp which it then processes to make paper or board.
Intermittent Board Machine
A machine for producing sheets of thick board by winding the web formed on a Fourdrinier wire or cylinder mould (s) around a making roll to form a sheet consisting of several layers. When the thickness is sufficient the layers are cut, so forming a sheet which is removed from the machine for drying and any further processing.
Internal Bonding Strength
Determines how strongly the coating is fused to the body stock. Caused by long periods of hydration, paper with high internal bonding strength resists picking during the printing process
Internal Fibrillation
Loosening of internal bond within a fiber.
Internal Sizing
Occurs when sizing materials are added to the water suspension of pulp fibers in the papermaking process. Also known as Beater, or Engine sizing.
International Paper and Board Sizes
Also known as ISO sizes are widely used in metric countries. ISO standards are based on a rectangle whose sides have a ratio of one to the square root of 2 (1.414). No matter how many times a sheet of these proportions is halved, each will retain the same constant proportions. There are three ISO series A, B, and C.

The A Series: The A series is for general printed matter including stationary and publications.

SIZE Millimeters

4A0 1682 x 2378
2A0 1189 x 1682
A0 841 x 1189
A1 594 x 841
A2 420 x 594
A3 297 x 420
A4 210 x 297
A5 148 x 210
A6 105 x 148
A7 74 x 105
A8 52 x 74

The B series: The B series is about half way between two A sizes. It is intended as an alternative to the A series, used primarily for posters and wall charts.

SIZE Millimeter

B0 1000 x 1414
B1 707 x 1000
B2 500 x 707
B3 353 x 500
B4 250 X 353
B5 176 x 250
B6 125 x 176
B7 88 x 125
B8 62 x 88
B9 44 x 44
B10 31 x 44

The C series: The C series is used for folders, post cards and envelopes. C series envelope is suitable to insert A series sizes.

SIZE Millimeter

C0 917 x 1297
C1 648 x 917
C2 458 x 648
C3 324 x 458
C4 229 x 324
C5 162 x 229
C6 114 x 162
C7 81 x 114
C8 57 x 81

RA Series Formats
RA0 860 x 1220
RA1 610 x 860
RA2 430 x 610
RA3 305 x 430
RA4 215 x 305

SRA Series Formats
SRA0 900 x 1280
SRA1 640 x 900
SRA2 450 x 640
SRA3 320 x 450
SRA4 225 x 320

DL 110 x 220
C6 114 x 162
C5 162 x 229
C4 229 x 458
C3 324 x 458

ISO Brightness
The brightness of paper and board measured at a wavelength of 457 nanometers under standard conditions.
Ivory Board
High-quality board made in white or colors with a bright, clear appearance, particularly used for visiting cards and similar high-class printed work. Original Ivory Board was and still is made in Holland, although the grade is made in many countries.
Copypaper logo