Links to pastel arts websites; plus an art paper lesson

Glossary

Since 1892, Strathmore has designed papers that are the preferred choice of professional artists, art teachers and knowledgeable amateurs. Most Strathmore Artist Papers are made in our own mills, where each run is tested by machine and by hand. We hope this quick reference guide and glossary will be useful in helping gain a better understanding of common artist paper terms and the Strathmore product offering.

Acid Free Paper - Paper manufactured using alkaline papermaking technology. Acid free papers are buffered with an alkaline reserve, such as calcium carbonate, to neutralize acid compounds absorbed from the atmosphere or formed through natural aging.

Archival Paper - Paper manufactured to provide the ultimate resistance against natural aging. The most important characteristics are: no groundwood or unbleached pulp, a minimum pH of 7.5, and additional alkaline reserve of 2%.

Basis Size - Sizes based on traditions/customs which represent the industry standard for a specific paper grade. For example, the basis size of watercolor paper is 22" x 30".

Basis Weight - The weight in pounds of a ream (500 sheets) of paper in a given basis size. Thus, a 140 lb. watercolor paper will be one in which a ream of 22" x 30" sheets actually weighs 140 pounds.

Bond - A term that has grown to be a catch-all for many different types of paper. Essentially, Bond is a grade of writing or printing paper with varying degrees of translucency, known for strength, durability and permanence, while remaining comparatively light weight. Originally used in the printing of corporate bond certificates. In the art field, it is extensively used for general layout and visualizing purposes.

Bristol - Artist Bristol generally describes drawing paper that is pasted. Two or more sheets are pasted together to form 2-ply, 3-ply, etc. Sheets are pasted into Bristol to achieve stiffness, strength and to form a sheet with two identical useable (felt or top) sides.

Calendering - A process that takes place at the end of the papermaking machine. The paper is passed through a stack of steel rollers which gives it more uniform thickness (caliper). By varying the number of rolls used, and the pressure applied, degrees of smoothness can be achieved.

Caliper - The thickness of a sheet of paper, expressed in thousandths of an inch (.001).

Cold Press - A term used to describe the medium surface of certain textured paper used for watercolor work.

Deckle Edge - A decorative feathered edge produced during the papermaking process.

Felt Side - The side of paper that does not contact the carrying wire while traveling across the wet end of the papermaking machine. Also known as the “top side,” it is considered the preferred working side of a sheet of paper.

Fourdrinier - The formal name for a papermaking machine that forms a continuous web of paper on a moving wire screen. The vast majority of paper manufactured in this country is made on Fourdrinier machines.

Furnish - A term to describe the mixture of fibrous materials (pulp), sizing, fillers, dyes, other additives and water that eventually is processed into paper. The consistency of prepared oatmeal, furnish is what is fed onto the moving wire of a Fourdrinier paper machine or Cylinder machine.

g/m² - A unit of measure for the weight of paper in the metric system. It is the weight of one square meter expressed in grams. A 140 lb. 22" x 30" watercolor paper is equivalent to 300 g/m².

Grain Direction - The direction in which the majority of fibers lie in a finished sheet of paper corresponding to the direction the wire travels on a papermaking machine. Handmade papers have no grain direction.

Hot Press - Used primarily in describing watercolor papers with a very smooth surface.

Laid Finish - Describes a watermarked series of parallel, vertical and horizontal impressed lines in a sheet.

Lignin - An organic substance which acts as a binder for cellulose fibers in wood and certain plants, adding strength and stiffness to cell walls. Lignin is undesirable in the production of fine, permanent papers because it reacts with light and/or heat to produce henols (alcohols) and acids, which cause deterioration and embrittlement of the paper.

Mould (Mold) Made - Although originally describing a handmade process, today “mould made” papers are produced on a Cylinder machine. Cylinder machines differ from Fourdriniers only in the way the pulp is applied to the wire.

Opacity - The property of a paper that minimizes or prevents the passage of light through the sheet.

pH - This is a chemical term, defining the acid-alkaline range of any substance. A lower pH indicates acidity, a higher figure shows an alkaline condition. A pH reading of 7.0 indicates neutrality.

Plate Surface/High Surface - For a special, uniformly smooth finish, sheets of paper are interleaved with highly polished metal plates to make a stack, or “book.” The “book” is then pressed repeatedly between steel rolls under great pressure, imparting the smoothness of the metal plate to a paper’s surface. Plate surface papers are ideal for pen and ink, airbrush, and mechanical layouts.

Ply - A single thickness (sheet) of paper. Artists’ papers and mounting boards, as well as other grades, are identified as 1-ply, 2-ply, etc. As each ply is pasted together the increased thickness and stiffness is described by the number of plies.

Post-Consumer Material - Paper, paperboard and fibrous wastes from retail stores, office buildings and homes after they have passed through their end‑usage as consumer items.

Pulp - Cellulose fiber material extracted by chemical or mechanical means from wood, cotton or other organic or synthetic sources. Pulp provides the fiber content in the furnish, which is used to form paper.

Rough Surface - A term used to describe a coarse, textured paper. Often used by artists when discussing the surface characteristics of watercolor paper.

Size (Sizing) - Additive substances such as starch or animal glue which are applied to the surface of the paper (surface sizing) and/or added to the furnish (internal sizing). Sizing is applied to the paper to improve the drawing, painting or printing qualities such as moisture hold out and paper strength.

Smooth Surface - A paper with a very smooth, hard finish. Ideal for pen and ink, marker, airbrush and mechanical layouts.

Vellum Surface/Medium Surface/Regular Surface/Kid Surface - A term used to describe the finish of a sheet of paper, with a minimum to moderate tooth. Ideal for pencil, charcoal, airbrush, pastel, crayon, and pen and ink, (not requiring a solid line).

Wire Side - The reverse of felt side. It is the side of the sheet of paper that comes in contact with the Fourdrinier wire on the wet end of the papermaking machine.