Testing Papers for Watercolour and Mixed Media

Why the paper deserves as much attention as the paint

Most of us begin with whatever pad is on the shelf and spend years blaming our brushes. The truth is that paper does more of the work than any other supply you own. It decides how far a wash travels, how pigment settles, whether you can lift a mistake, and whether a second layer will glide on or tear the surface to shreds. Lovely paint on a poor pad looks muddy; a modest paint on good paper looks considered.

Four things change between one sheet and the next: weight, sizing, texture and fibre. Once you can read those, choosing paper stops being a gamble.

Weight: the difference between a flat wash and a buckled mess

Weight is given in grams per square metre (gsm), and sometimes in pounds (lb). As a rough guide, 190gsm is about 90lb and 300gsm about 140lb. Heavier paper resists cockling, and that single fact shapes your whole technique.

• Up to 200gsm: light and affordable, ideal for sketchbooks, dry brush and small studies. Flood it with water and it will ripple like a tide chart.
• 200–250gsm: a decent middle ground for beginners. Fine for controlled washes, but still worth taping down.
• 300gsm: the hobbyist's sweet spot. It takes generous wet-in-wet work, holds a taped edge and rarely needs stretching. Most of my day-to-day work happens here.
• 425gsm and upwards: heavy, board-like, luxurious. Barely cockles at all, though you pay for the privilege and it is slower to cut.

If you love loose, soaking washes, buy 300gsm or heavier. If you prefer lighter paper for sketching, either tape it to a board with gummed tape or stretch it properly — soak it, lay it flat, and let it dry before you paint.

Sizing: what decides whether your paint sits or sinks

Sizing is a binder, traditionally gelatine, added to the pulp or applied to the surface so the paper does not drink water like a kitchen roll. It is the least discussed quality and the one that changes handling most.

• Internally sized: mixed into the pulp, so the whole sheet resists water evenly. Reliable and predictable.
• Hard sized (heavily surface sized): paint sits up on the surface. Edges stay crisp, glazes stay clean, and lifting a mistake with a damp brush actually works.
• Soft sized: water sinks in fast, giving soft, blooming edges and lovely wet-in-wet effects. Wonderful for expressive work, frustrating when you want a hard edge or a clean lift.

A simple check on any new sheet: paint one bold stroke, leave it thirty seconds, then try to lift a corner with a clean damp brush. Comes away easily? Hard sized. Stains the paper? Soft sized.

Texture: hot pressed, cold pressed and rough

This is the choice most painters make by instinct, and it is largely about how much tooth the surface gives you.

• Hot pressed (HP): smooth, almost plate-like. Beautiful for fine detail, botanical studies, pen and wash, and any subject needing neat, deliberate marks. Pigment sits on top, so washes can look slightly flat until you learn to build them.
• Cold pressed (also called NOT, or "grain fin"): a gentle, regular tooth. The most forgiving all-rounder, and the surface I would recommend to anyone unsure what to buy. It gives a little sparkle to dry brush without fighting your brush.
• Rough: pronounced dimples. Granulating pigments gather in the hollows and create texture you simply cannot paint by hand. Superb for landscapes, stonework and expressive florals; hopeless for tidy lettering or fine line work.

Fibre: cotton, wood pulp and the mixed media question

Cotton (often called rag) papers are absorbent, springy and remarkably forgiving. They lift cleanly, tolerate scrubbing and keep their colour. Wood pulp papers are cheaper, perfectly good for practice and studies, but can pill or scuff if you overwork them.

For mixed media the demands tighten. Acrylics, gesso, inks, collage and coloured pencil all pull at the surface in different ways, so you want at least 300gsm, a hard size, and preferably cotton. A few practical rules:

• Avoid very rough paper for fine ink or pencil work — the nib catches and lines wobble.
• Choose heavier sheets (400gsm+) if you plan to work on a board without taping; acrylics and heavy washes will cockle lighter paper.
• Test any paper with a thin wash of gesso before committing a finished piece to it.
• Keep a cheap pad for thumbnails so your good cotton paper stays for real paintings.

A ten-minute test you can run on any new pad

Before you trust a new paper with a proper painting, cut one sheet into quarters and put it through its paces. Label each test in pencil as you go.

• Wet-in-wet blob: wet a square, drop in strong pigment and watch how far it blooms. Fast spread suggests soft sizing.
• Dry brush stroke: drag a nearly dry brush across the surface. Good tooth leaves a broken, sparkling mark.
• Lift test: paint a strong square, let it dry, then lift with a damp brush. Note how much colour comes away.
• Scrub test: work a small area with a stiff brush and water. If fibres ball up quickly, keep this paper for gentle work only.
• Layer test: paint three thin glazes over one another. Glowing colour means good sizing; muddy or patchy means the surface is breaking down.
• Mixed media corner: swipe a little gesso, ink, acrylic and pencil across it to see how the surface copes.

Do this once and you will never buy blind again. Keep the labelled swatches in a folder — within a year you will have a personal reference library of every paper you have tried, and a clear answer to the only question that matters: which surface makes your painting style feel effortless?