Polyester Canvas: Honest Answers to the Hard Questions Traditional Painters Ask

Traditional painters are right to question new materials. Linen and cotton have centuries behind them, and a painter who has spent decades learning one surface has every reason to be sceptical of another.

So here are the hardest questions we get about polyester canvas, answered straight, with sources you can check.

---

Why don't ACF canvases have keys?

Keys are the small wedges pushed into the corners of a stretcher to re-tighten a canvas once it goes slack. They exist to fix a problem.

Conservators are not keen on them. The Canadian Conservation Institute is direct about it:

"keying out is not a procedure that is recommended for a painted canvas."

Their guidance explains why: tapping keys can damage the paint, the ground and the canvas itself.

So we went the other way. Rather than give you a tool to fix sag after it happens, we built a canvas that does not sag. ACF uses a fixed strainer, and our 100% polyester fabric holds its tension, so there is nothing to key out.

---

Aren't linen and cotton fine?

They have served painters for centuries, and plenty of paintings survive on them. But a large part of a paintings conservator's work is repairing what natural fibres do over time. They take on moisture, slacken, tighten again, and grow brittle with age.

The standard reference for the profession is The Conservation of Easel Paintings (Stoner and Rushfield, eds., Routledge, 2012). In chapter 5, "History of Fabric Supports", Christina Young names the material she considers the best way forward. Polyester, she writes,

"exhibits the best combination of properties and provides the most promising starting point to improve the performance of artists' canvas"

In the same sentence she adds that it had yet to match linen or cotton in feel and appearance.

That gap, the feel and the look, is exactly what ACF set out to close.

---

Isn't polyester canvas old news?

Yes. Polyester has been used as a painting surface for decades. Some painters will remember small makers stretching it long ago.

The fabric was never the problem. The surface was. Polyester fibre is smooth and paint does not naturally grip it.

Bigger companies than us have tried to crack synthetic canvas, and chapter 5 of The Conservation of Easel Paintings names them:

• Daler-Rowney worked with Haywood Sailcloth on an acrylic-primed polyester. The project was abandoned because certain media bled into the canvas.
• Winsor & Newton sold Rayoc, a viscose-primed canvas designed to replace animal glue sizing. Manufacturing difficulties and high cost led to its withdrawal.

ACF's coating was developed over years with a well-known South African oil painter, and tested by him to destruction. It is built into the fabric at manufacture, so the canvas arrives ready to paint.

For the full story of why paint struggles on bare polyester and how that was solved, read Does Paint Stick to Polyester Canvas? The Honest Answer.

---

Can't I just size polyester myself?

You can. It is harder than it sounds.

A common suggestion is Golden GAC 200, a hard acrylic polymer used to improve adhesion. But Golden's own product guidance says its preferred use is on rigid supports, and advises caution on canvas, linen or paper, because rolling or flexing can crack it. Several art retailers list it as not recommended for stretched canvas.

So doing it yourself means choosing the right product, sometimes blending mediums to keep the film flexible, then priming on top. Every one of those steps is a chance for the surface to fail years after the painting is finished.

We do that work at manufacture, so you don't have to.

"As an artist who normally spends hours gessoing, sanding, and prepping my canvases, I immediately noticed the difference with ACF. The surface is much smoother than the regular canvases I usually buy and felt ready to draw on straight out of the box." LexKittenArts

---

Why MDF instead of solid wood?

Wood has grain, and grain moves with humidity. That movement is what twists and warps stretcher bars.

Engineered MDF has no grain, so there is nothing for it to warp along. That is a design choice, not a cost saving. Our strainers use certified MDF from the mills, with bevelled edges so no bar line prints through under the brush.

---

Where is ACF made?

ACF was founded in South Africa in 2013, working directly with artists. Our strainers are made and our canvases stretched at our own factory in Lanseria, South Africa. Stock is shipped in bulk to the UK and USA and delivered locally, with no import duties for you.

Every canvas carries a 100% guarantee on materials and workmanship.

---

The takeaway

Every one of these questions is fair. Linen and cotton are familiar, keys are traditional, and polyester has been tried before.

But the conservation field named polyester as the most promising way forward, the big manufacturers who tried to get there stopped short, and the tools painters use to fix slack canvas are the same tools conservators warn against.

We did not stop. That is the whole difference.

Read next

• Does Paint Stick to Polyester Canvas? The Honest Answer
• Art materials were reinvented by science. Canvas wasn't.
• Why polyester is the best artist canvas material

---

Or test it yourself

Both are 100% polyester in warp and weft, pre-coated with our own gesso, on a strainer that holds its shape.

---

Sources

• Young, C., "History of Fabric Supports", chapter 5, in Stoner, J.H. & Rushfield, R. (eds.), The Conservation of Easel Paintings, Routledge / Taylor & Francis, 2012.
• Canadian Conservation Institute, CCI Notes 10/9, Keying Out of Paintings. Link
• Canadian Conservation Institute, Caring for Paintings, Preventive Conservation Guidelines for Collections. Link
• Golden Artist Colors, GAC 200 product information. Link
• Jackson's Art, Golden GAC 200 Acrylic Polymer product listing. Link