Skip Ribbon Commands
Skip to main content


Paper & Pulp Dictionary Glossary "H"

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


Half Fold
The half fold is commonly used for brochures and greeting cards. For cover weight paper, a score is usually required to produce a smooth folded edge.  For picture of this type and other fold please visit
Half + Letter Fold
This fold is perfect for newsletters. An 11" x 17" sheet folded this way has only one open side and fits into a #10 envelope. The newsletter looks good and is easy to handle. For picture of this type and other fold please visit
Half Tone
Picture with gradations of tone, formed by dots of varying sizes in one color.
Handmade Paper
A sheet of paper, made individually by hand, using a mould and deckle.
Hard Cook
Undercooked pulp with respect to target conditions.
Hard Pulp
Chemical pulp with a high lignin content.
Hard Sized Paper
Paper treated with high degree of internal sizing.
Wood from trees of angiosperms class, usually with broad leaves. Trees grown in tropical climates are generally hardwood. Hardwood grows faster than softwood but have shorter fibers compared to softwood.
Head Box or Flow Box or Breast Box
The part of the paper machine whose primary function is to deliver a uniform dispersion of fibers in water at the proper speed through the slice opening to the paper machine wire.

Heart Wood
The dark colored , center of a tree trunk, consisting of dormant wood.
Heat Set Web
An offset printing process done on a web of paper supplied in a roll. The term heat set originates from the inks used in the process. They contain high amounts of solvent flashed off in ovens to dry at very high speeds. Web presses perfect or print both sides of the sheet simultaneously.
Heat Transfer Paper
The paper used in Thermal transfer printing (Sublimation printing).
A constituent of woods that is, like cellulose, a polysaccharide, but less complex and easily hydrolysable.
Herbaceous Plants
Non-woody species of vegetation, usually of low lignin content such as grasses.
An irregularity in the ink coverage of a printed page. Hickeys are caused by paper or pressroom dust, dirt, or pick out on the printing blanket, all of which prevent the ink from adhering to the paper surface.
High Finish
Smooth finish applied to paper to improve the printing surface.
Hold Out
Resistance of paper surfaces to the absorption of ink. High Hold Out offers higher resistance to ink absorption. Regular Hold Out allows greater ink absorption.
The total carbohydrate fraction of wood — cellulose plus hemicellulose.
Printining process by which great continuous 3D depth is achieved using textures and patterns.
A hood covering the paper machine drying section and designed for moist air removal.
Hot Melt
A type of glue or adhesive applied while hot/warm.
Hot Groundwood Pulp
Mechanical pulp produced by grinding logs that have been pre-treated with steam.
The prolonged beating or refining of cellulose pulp in water to reduce it to a semi-gelatinous mass.
Hydrogen Peroxide Bleaching
A method in which pulp is bleached in an alkaline environment with hydrogen peroxide (H2O2), sometimes using oxygen reinforcement. The method considerably reduces the need for chlorine-containing chemicals in the final bleaching of chemical pulps.
Having strong affinity for water.
Lacking affinity for water.
An equipment used to slush broke/paper in to pulp.
Having the property to absorb water vapor from the surrounding atmosphere. Most of the papers (except glassine, greaseproof or wet strength etc.) are hygroscopic in nature.
Copypaper logo