If you bought a stretched canvas from an art store, it is almost certainly already primed and you do not need to do anything to it. That is the honest answer to the question most people are asking, and it saves a lot of unnecessary work.
Surface preparation matters in the cases where it matters: raw canvas, bare wood, glass, plastic, stone, or when you want to change how a canvas behaves. Here is what each of those needs and why.
Support and absorbency
The surface you paint on is called the support. It can be canvas, board, panel, paper, or almost anything else. What separates one support from another, in practical terms, is how much liquid it soaks up.
A highly absorbent support drinks water out of the paint. Thin washes sink in and dry flat and matte, and heavy dilution can leave the pigment sitting in the fibers rather than bound in a film. A non-absorbent support does the opposite: paint sits on top, stays glossy, dries slowly, and can lift off if it never got a mechanical grip.
Acrylic used thickly, straight from the tube, will stick to nearly anything that is clean and not oily. It is when you start adding water that the support's absorbency changes the result. That is the whole reason priming exists.
Canvas: cotton or linen
Almost all ready-made canvas is cotton duck. It is the cheaper of the two, it has a slightly irregular weave, and it is perfectly good for most work.
Linen costs considerably more. In exchange it is stronger, more dimensionally stable, and has a finer, more even weave, which is why it is the traditional choice for large paintings and for work meant to last a long time. If you have read that linen is the cheap option, that is backwards.
Weight matters more than most beginners realize. Very light canvas can be close to paper: it has little texture, it flexes under the brush, and it will ripple if you put much water on it. Heavier canvas holds its tension, takes the brush better, and gives you the slight tooth that makes dry-brush work possible.
When a canvas actually needs gesso
Acrylic gesso does two jobs. It seals the fibers so paint does not sink straight through, and it gives the surface a slight tooth for the paint to grip.
You need to apply it when:
- You are working on raw canvas bought by the yard, or on bare wood or board.
- You are painting in oil on fabric. Oil degrades unprimed canvas fibers over time, so a sealed ground is not optional. Acrylic does not do this, which is why acrylic on raw canvas is a legitimate choice rather than a mistake.
- You want to change the texture — more coats sanded smooth for fine detail, or a heavier gesso left rough for landscape work.
You do not need it on a pre-primed canvas simply because someone told you priming is a step. It already has two or three coats on it. If you have been painting on store-bought canvas without gessoing and the results look fine, they are fine. Our separate guide covers what gesso is and what it does in more depth.
How to prime, in order
- Stretch first, prime second. Gesso stiffens the fabric. If you prime a loose canvas and stretch it afterwards, the ground cracks and flakes along the pull.
- Clean the surface. Dust and loose fibers only. Wipe with a dry or barely damp cloth. Do not soak it.
- Stir the gesso. It settles in the tub. A little water thins the first coat and helps it key into raw fabric, but keep it thin rather than watery.
- Brush it on in one direction with a wide brush, in a thin even coat. Thick coats crack.
- Let it dry properly — around an hour in a warm room, longer in a cold or humid one.
- Sand lightly with fine paper if you want smooth. Skip this if you want texture.
- Second coat at right angles to the first. Two or three coats is plenty for most work.
Stretching your own canvas
Stretching is cheaper than buying ready-made and takes some practice. You need stretcher bars, rust-resistant staples and a staple gun, canvas pliers, scissors, and something to check that the corners are square.
Assemble the bars into a rectangle, pushing the joints home by hand or tapping gently so you do not dent the wood, and check all four corners with a square before you go further. Lay the canvas flat, put the frame on top, and cut with two to three inches of spare fabric on every side.
Staple the middle of one side, then the middle of the opposite side pulling firm with the pliers, then the two remaining middles, and work outwards in that alternating pattern towards the corners. Fold the corners last. Working outwards from the middles is what keeps the tension even; going around the edge in one direction pulls the whole thing out of true.
Other surfaces
Wood and board. Plywood, hardboard and MDF all take acrylic well and are smoother than canvas. Prime bare wood, because sap, resin and tannins can bleed through and stain a painting from underneath. Sand first if you want a smooth ground.
Paper. Acrylic works on paper, but thin paper buckles, and heavy water will cockle or tear it. Use something around 300 gsm, which is 140 lb, or a paper made specifically for acrylics. Watercolor paper handles water well and needs no priming, though its absorbency will flatten your washes. Choose acid-free.
Canvas board and canvas pads. Canvas board is primed fabric glued to a rigid panel — cheap, portable, good for studies. Canvas pads are paper embossed with a canvas texture, not fabric, which is why they cost less and will not last as long. They are different products and worth telling apart before you buy.
Glass. Non-porous and shiny, so ordinary acrylic will sit on the surface and can be picked off with a fingernail. Clean it with alcohol or vinegar first, because skin oil alone will stop paint adhering, and use a medium made for slick surfaces such as an acrylic polymer designed for glass and tile. Seal when dry. Tape or frame sharp edges before you start.
Ceramics. Fine for decorative pieces. Prime porous bisque or it will drink the paint, and seal the finished piece. One firm limit: craft acrylic is not food safe, and no home oven or craft sealer makes it so. Keep paint off any surface that touches food or lips, and use kiln-fired glaze for anything you actually eat or drink from.
Plastic. The hardest of the lot, because there is nothing for the paint to grip. Matte plastics work better than glossy ones. Use a spray primer made for plastic, and seal afterwards.
Stone. Straightforward and forgiving. Find a smooth stone, wash it without soap or detergent, let it dry completely, gesso it if you want the colors to stay bright, and seal it afterwards — especially if it is going outdoors.
Walls. Use paint made for walls. Artists' acrylics are formulated for permanence on a small scale, not for scrubbing, coverage or exterior exposure, and they are an expensive way to cover a large area.
The one rule about oil and acrylic
Oil paint over dry acrylic is fine, and painting oils onto an acrylic-gessoed ground is standard practice.
Acrylic over oil is not. Acrylic is water-based and will not bond to an oily surface. It may look attached while it dries and lift off in sheets later. The rule is easy to remember in one direction only: oil on top of acrylic, never acrylic on top of oil.
Common questions
I have never gessoed a shop-bought canvas and my paintings look fine. Am I doing something wrong?
No. Ready-made stretched canvas comes primed. Extra gesso is for changing the texture or working on raw material, not a compulsory step.
Will heavily watered acrylic peel off later?
Not on an absorbent ground in the early layers, where the diluted paint soaks in and binds. The risk is in the final thin glazes over an already sealed, glossy surface. For those, thin with an acrylic glazing medium rather than water, so the pigment stays inside a proper paint film.
Can I paint on fabric from a fabric store?
Yes. Prime with gesso or a clear acrylic medium if you want the weave and pattern to show through, and mount thin fabric onto board with acrylic medium rather than trying to stretch it. Avoid upholstery fabric unless you prewash it, since stain-resistant finishes stop primer keying properly.
What is the easiest medium to start with?
Acrylic. It dries fast, cleans up with water, and mistakes can be painted over once dry. Watercolor is the least forgiving, and oil demands patience between layers. If you would rather skip the surface question entirely, a paint by numbers kit arrives with the canvas already primed, printed and ready.
