Whether you’re a seasoned water colour painter or new to the discipline, knowing the most important water colour surface terminology will ensure you choose the ideal surface for your work.

Acid free

Produced by using cotton linter or archival grade cellulose fiber, acid-free paper is pH neutral, which is essential to retain the long term quality and whiteness of the paper. 


Water colour papers are traditionally white, allowing the maximum amount of light to be reflected back through the wash. Conversely, tinted papers give a mellow tone to a painting.

Deckle Edges

Irregular edges that provide a traditional, hand made look to the paper. Deckle edges can be made on the cylinder mould paper machine or by tearing the paper.

External sizing

This refers to a layer of sizing on the surface of paper which enables water colour film to sit atop it, look brighter and allows it to be sponged off by the painter.  External sizing is also known as surface sizing and creates a harder surface, which allows scraping and rubbing without damaging the paper itself.

Internal sizing 

Internal sizing reduces the absorbency of paper fibers by chemically bonding to them.

Mould-made paper

Some paper is formed with a cylinder mould. Fibers are arranged at random to mimic a hand-made sheet, and the arrangement provides dimensional stability, reducing cockling (wrinkling).

Surface: Rough grain

This is the heaviest texture of paper, close to handmade paper. It is embossed from the surface when the sheet is being dried and is used by water colour artists who rely on a more textured surface.

Surface: Cold Pressed

Cold Pressed paper has a light texture. It is the most popular texture used by water colourists. This paper often produces the brightest water colour paintings because its increased surface area holds more colour, therefore reflecting more light.

Surface: Hot Pressed

Illustrators and miniaturists use Hot Pressed papers; a smooth paper finish blends with their images more comfortably.

Water Colour Blocks

Water Colour Blocks consist of several paper sheets of paper glued around all four edges to keep paper flat whilst painting, eliminating the need to stretch paper prior to painting. A small section is left unglued to enable a palette knife to remove the finished work, one sheet at a time. Blocks are excellent for painting en plein air.


Heavier paper is more resilient to wear and tear, as there is more interwoven fibre in a heavy sheet. Lightweight papers should be stretched if you expect to use lots of water. 

Watercolour paper weight measurement: Imperial and Metric

Imperial weight is that of Pounds per ream of 500 sheets of Imperial sized 30" x 22" paper.   The most popular weight of water colour paper might be 140lb.
The Metric weight is grams per square metre (gsm). A 140lb. paper is equivalent to 300gsm.