How to Frame a Canvas Painting Unstretched: 5 Methods

Unstretched canvas paintings arrive in many forms: a rolled painting bought on holiday, a piece shipped in a tube, a study on canvas paper, or your own work painted on loose canvas taped to a wall. They all share one challenge. Without a rigid structure, the fabric has nothing to keep it flat, so it cannot go straight into a frame.

This guide explains how to frame a canvas painting unstretched, comparing each method with step-by-step instructions, so you can pick the approach that suits the painting, your budget and your tools.

Before You Start: Assess the Painting

• Is there enough border? Stretching needs extra fabric around the image, ideally 2 to 3 inches on every side, to wrap around stretcher bars. Paintings cut close to the image cannot be stretched without losing part of it and are better mounted or floated.
• How was it stored? Rolled paintings should be unrolled slowly at room temperature. If the paint is thick or the canvas has been rolled tightly for a long time, cracks are possible. Unroll gradually and stop if you hear crackling.
• What is it painted with? Acrylic on canvas is generally flexible. Older oil paintings can be brittle. Treat valuable or old paintings as conservation work and consult a professional framer or conservator.
• Is it canvas or canvas paper? Canvas paper is thin, textured paper; it frames more like a print than a canvas.

Flattening a Rolled Painting

Unroll the painting face-up on a clean, flat surface. Place a sheet of clean paper or silicone release paper over it and lay flat boards or large books around the edges (not directly on thick paint) to relax it. Leave it for 24 to 48 hours in a room with moderate humidity. Avoid irons and direct heat on painted surfaces.

Comparing Methods for Unstretched Canvas

Whichever method you choose, the outer frame is usually wood, which is easy to cut, join and fasten into. Our guide to the right wood frame for a canvas painting covers profile depths and finishes that suit each approach.

Method 1: Stretch the Canvas, Then Frame It

This is the most common way to frame a canvas painting unstretched, and the result looks just like a painting that started on stretchers.

What You Need

• Stretcher bars in the right lengths (measured to the image size, not the fabric size).
• A staple gun with 3/8-inch or similar staples.
• Canvas pliers (strongly recommended).
• A carpenter’s square or tape measure.
• A soft, clean surface to work on.

Steps

1. Measure the image. Decide whether the image will end at the front face of the stretcher or wrap around the sides. For a frame that covers the edges, size the stretcher to the image area.
2. Assemble the stretcher. Push the corner joints together and check squareness by measuring both diagonals; they should match.
3. Position the canvas. Lay the painting face-down on a clean, padded surface. Center the stretcher on top, lining up the image edges with the bars.
4. Staple the centers. Fold one side over the bar and staple at its center. Then pull the opposite side firmly with canvas pliers and staple its center. Repeat on the other two sides.
5. Work outward. Add staples about 2 inches apart, working from the centers toward the corners and alternating between opposite sides to keep tension even.
6. Fold the corners. Tuck each corner into a neat fold and staple it to the back.
7. Check the front. The surface should be taut with no ripples. Tap corner keys gently if extra tension is needed.
8. Frame it. Set the stretched painting into a traditional or floater frame and secure it with offset clips or screws. Our main guide on framing a canvas painting walks through this final stage in detail.

Tips for Stretching a Painted Canvas

• Painted canvas is less forgiving than blank canvas. Pull firmly but not so hard that paint cracks along the edges.
• Thick paint near the edges can crack when folded around bars. Consider a slightly larger stretcher or a different method if the image runs right to the edge with heavy texture.
• A professional framer can stretch a painting for you if it is valuable or large.

Method 2: Mount the Canvas on a Rigid Board

Mounting adheres the canvas to a flat, stiff panel. It suits small and medium paintings and works even when there is no extra border.

What You Need

• A rigid board slightly larger than the painting: acid-free foam board, gessoed hardboard or a wood panel.
• Acrylic gel medium (matte or soft gel) or an archival mounting adhesive.
• A brayer or soft roller and a clean plastic scraper.
• Silicone release paper and heavy books or boards for weighting.

Steps

1. Cut the board to size. Seal hardboard or wood with a coat of gesso or acrylic medium on both sides to reduce warping.
2. Brush a thin, even layer of gel medium onto the board.
3. Place the canvas face-up on the board, starting from one edge and lowering it gradually to avoid air bubbles.
4. Cover with release paper and roll from the center outward with a brayer, pressing gently.
5. Weight the whole surface evenly with boards and books and leave for 24 hours.
6. Trim any overhang with a sharp craft knife, or leave a border.
7. Frame the mounted piece in a standard frame of the right rabbet depth, with or without a mat.

Note that adhering a painting to a board is not easily reversible. For valuable work, ask a framer about reversible mounting methods.

Method 3: Float the Canvas in a Shadow Box

Floating lets the entire painting, including its raw or uneven edges, show against a background inside a deep frame. It looks especially good for paintings with interesting edges, such as deckled canvas or work painted on loose fabric.

1. Choose a shadow box frame with enough depth to keep the glazing (if any) off the paint surface.
2. Cut a backing board covered with acid-free mat board or linen fabric in a neutral color.
3. Attach the canvas to the backing with hidden hinges: small strips of linen tape or fabric adhered to the back of the canvas top edge, then fixed to the backing. Alternatively, mount the canvas on a slightly smaller raised board (a “float block”) so it stands forward from the background.
4. Position it centered with an even margin.
5. Close the frame and attach hanging hardware.

Method 4: Mat and Frame Like a Print

For canvas paper, canvas pads and thin unstretched pieces, a standard picture frame with a mat works well.

1. Cut a window mat or buy a pre-cut mat with an opening slightly smaller than the image.
2. Hinge the painting to a backing board along the top edge with acid-free tape.
3. Place the mat over it so the mat covers the outer edges.
4. Insert into a frame with glass or acrylic glazing. The mat keeps the glazing off the paint surface.

Make sure the paint is fully dry and cured before putting it behind glazing, or moisture can be trapped.

Method 5: Hanger Bars for Informal Display

Magnetic or clamp-style poster hanger bars grip the top and bottom edges of a flat canvas. This is quick, inexpensive and does not alter the painting, making it a good temporary solution while you decide on permanent framing. The canvas may curl at the sides over time.

How to Frame a Large Unstretched Canvas

Large rolled paintings, roughly 30 inches or more on a side, change the calculation. Mounting becomes impractical because big rigid boards are heavy, prone to bowing and hard to handle, so stretching is usually the better route. A few adjustments help:

• Use heavy-duty stretcher bars with a cross-brace on any side longer than about 30 to 36 inches, so the frame stays square and flat.
• Recruit a second person. One holds tension while the other staples, which gives far more even results on long sides.
• Unroll the painting fully a day or two ahead so it relaxes before stretching.
• Choose a frame with a sturdy molding and reinforced corners, and hang it with a cleat or two hooks rather than a single nail.

If the painting is valuable or the paint is thick, this is a good job to hand to a frame shop, since large canvases are harder to tension evenly at home.

Measuring for an Unstretched Canvas Frame

• Stretching: measure the visible image you want on the front; the fabric beyond that wraps around the bars.
• Mounting: measure the full canvas or the area you intend to show, then add a mat border if desired.
• Floating: add 1 to 3 inches of margin on each side to the canvas size for the frame’s inner dimension.
• Matting: mat opening slightly smaller than the image (about 1/4 inch overlap per side).

DIY Frame Options

If standard frames do not fit your painting, building your own is an option. Simple strip frames, floater frames and box frames can be made with basic woodworking tools. Our guide on making a frame for a canvas painting explains the cuts, joints and finishing steps.

Common Mistakes

• Stretching without enough border, which cuts off part of the image or leaves staples visible.
• Uneven tension, causing ripples that show from the front.
• Using household glue for mounting, which can yellow, bubble and stain.
• Glazing directly against paint, which can stick to the surface.
• Unrolling a cold or tightly rolled painting too quickly, risking cracks.
• Ignoring the back. A sealed dust cover and proper hanging hardware protect the painting long-term.

FAQs

How do you frame a canvas painting that is not stretched?

Stretch it onto stretcher bars and frame it as usual, mount it onto a rigid board and place it in a frame, float it inside a shadow box, or mat it behind glass like a print. The best choice depends on the border size and the look you want.

Can I frame a rolled canvas without stretching it?

Yes. Mounting it onto a board, floating it in a shadow box or matting it behind glass all work without stretching. Flatten it first by unrolling slowly and weighting it gently for a day or two.

How much border do I need to stretch a canvas painting?

About 2 to 3 inches of extra fabric on each side is typical for wrapping around stretcher bars and stapling to the back, depending on bar depth.

Is it cheaper to mount or stretch a canvas painting?

For small pieces, mounting onto a board is often cheaper and simpler. For larger paintings, stretching is more practical because large boards are heavy and expensive.

Should I put glass over an unstretched canvas painting?

For thin canvas paper or delicate media, glazing with a mat or spacers can protect it. For acrylic or oil paintings that are stretched or mounted, glass is usually unnecessary.

Can a framer stretch my rolled painting?

Yes. Many frame shops offer stretching services, which is a good option for valuable, large or delicate paintings.

Final Thoughts

An unstretched canvas painting gives you more framing choices, not fewer. Stretch it for a classic look, mount it for simplicity, float it to show raw edges, or mat it for thin canvas paper. Once you know which method fits, the frame itself makes the final impression, so browse our wood canvas frame guide to choose a finish and profile that complements the painting.