How to Assemble Your Stretcher Frame and Stretch a Canvas – A Step-by-Step Guide by HM Canvases

At HM Canvases, we understand that a perfectly prepared canvas is the foundation of your artistic expression. That's why we've created this comprehensive guide to help you assemble your stretcher frame and stretch your canvas with confidence, ensuring it meets the high standards your art deserves.   

These Are All The Things You Will Need

Everything You Will Need to Stretch a Canvas

• Stretcher Bars to the size of the canvas you want

• Cross Braces if needed

• Fabric - At least 26cm bigger than the size of the canvas you are making

• Drill or Screwdriver

• 1cm Screws

• Wood Glue

• Stretcher Pliers

• Scissors

• Rubber Mallet & Small Hammer

• Heavy Duty Stapler with 8mm Staples

• Tape Measure

• Staple Remover (optional)

• Sandpaper

• Wedges

Step 1: Assemble Your Stretcher Frame

• Putting Together Cross Braces (If Applicable)

  
  

  • If your frame is over 90cm (36 inches), you may have purchased cross braces for additional support. If your frame is smaller or you have no cross braces, please proceed to the next step.   

    
    

  • Notched cross braces should be assembled first. On a sturdy table or workbench, fit the two lap joints together.  

    
    

    

    Fitting the two Lap Joints Together - Glue & Screw

    
    

  • The joint can be secured with glue, countersunk screws, or staples. At HM Canvases, we recommend using glue and screws for maximum strength and durability.   

    
    

  • Ensure your fixings are on the side of the cross bars with the rebated ends, so they are not visible from the back of the canvas once the frame is assembled. This attention to detail ensures a professional finish.  

    
    
    
    

    

    This is the rebated end of a crossbrace

    
    

• Putting Together Your Frame

  
  

  • Lay your stretcher bars on a clean, flat surface with the centre slots facing upwards. If your frame is rectangular, arrange the bars with the two longest sides closest to you.

    
    

    

    Centre Slots Facing Upwards

    
    

  • Insert your assembled double cross bar into the first bar; if your frame is rectangular, ensure the short cross bar is inserted into one of the long stretcher bars and the rebated side of the cross bar end is facing towards the profiled edge of the stretcher bar.

    
    

    

    Inserting the Crossbrace into the Stretcher Bars

    
    

  • Please pick up the assembled part of the frame and turn it 180 degrees, then firmly push the frame into the second long stretcher bar. 

    
    

    

    Assembling the Second Stretcher Bar

    
    

  • Please pick up the frame again and turn it 90 degrees left or right.   

    
    

  • Carefully align the stretcher bars and the cross bars to the slots on the stretcher bar and push them in firmly. You may need a rubber mallet to tap the joints into place gently. Our stretcher bars are designed for ease of assembly.  

    
    

    

    Assembling the third stretcher bar

    
    

  • Pick up the remaining stretcher bar and push it into place on top of the frame, using the rubber mallet to join the joints securely.   

    
    

    

    Assembling the Final Side

    
    

• Squaring Your Frame

  
  

  • Before stretching, it's crucial to ensure your frame is square. This will prevent warping and provide a professional finish.   

    
    

  • The most accurate way to achieve this is by ensuring the distances from opposite corners of the frame are identical.   

    
    

  • Lay your frame face down on the table or floor.   

    
    

  • Double-check that the four corner joints are neatly butted together.   

    
    

  • Please verify that the cross bars are centred in their slots.

    
    

  • With the frame in front of you, hook the end of a tape measure over the back left corner of the frame and measure to the front right corner.

    
    

    

    Measuring the Diagonal

    
    

  • Note down the length and repeat the process from the back right to the front left corner.   

    
    

  • Note any difference between the two measurements. Hook the tape measure over the two corners with the longest distance between them and gently tap with the mallet to adjust the distance. Recheck both distances to confirm your frame is properly square.   

    
    

    

    Adjusting the Frame

    
    

Step 2: Stretch Your Canvas

Now that your frame is assembled and square, you can stretch your canvas. With HM Canvases, you're one step closer to turning your artistic vision into a masterpiece.   

• The Stretching Process:

  
  

  • Spread your canvas on a clean, flat surface and place your assembled stretcher frame on top, with the front side facing down.   

    
    

  • Trim the canvas around the frame, leaving enough fabric to go up the sides and approximately 5cm (2 inches) to fold over onto the back. For example, with a 45mm deep frame, allow approximately 10cm (4 inches) of extra fabric all around.  

    
    

    

    Fabric Allowance & Aligned Weave

    
    

  • Ensure the frame is still front side down, with the flat surface facing you. Align the frame with the weave of the fabric in the centre of your cut canvas.   

    
    

  • Begin by folding one side of the canvas over a short end of the stretcher bar (or any side if your canvas is square) and staple it at the centre of the stretcher bar. This first staple is crucial for creating initial tension and stability.  

    
    

  • Moving to the opposite side of the first staple. Use the pliers, and grip the canvas firmly. Pull tautly until a straight crease forms from the pliers to the stapled end. While maintaining tension with the pliers, staple the canvas at the top of the crease. This technique ensures a smooth, even stretch, which is crucial for achieving a professional finish.  

    
    

    

    Putting in the second staple. Notice the taught line between the two sides.

  • Move to an adjacent side and repeat the procedure, pulling firmly and stapling the canvas to the stretcher at the centre. This will create a triangle crease, and then a diamond crease with the fourth staple on the opposite long side.  

    
    

    

    Creating a Diamond Crease with a staple in each side.

  • Continue working outwards from the centre of the long sides. Position the pliers about 5cm (2 inches) to one side, pull tightly, and staple to the frame. Repeat this in both directions from the centre, then move to the opposite long side and continue the process.

    
    

    

    A Stapled Side

  • On smaller canvases, you may be able to staple an entire side at once. However, for larger canvases, rotate the canvas several times, stapling individual sections as you move towards the corners. This method helps maintain even tension and prevents warping, which is especially important for our larger, bespoke canvases.   

    
    

  • Pro Tip! Linen or printed canvases may require more closely spaced staples due to the limited stretch in the fabric. This ensures a secure and stable surface for your artwork.

    
    

    

    Trim the excess fabric

  • For a neat finish on the back of the canvas wrap, trim and neatly fold over any surplus canvas and secure it with a second row of staples. This attention to detail reflects the quality and craftsmanship we value at HM Canvases.   

    
    

  • Repeat this procedure on two opposing sides, stapling up to the edge.   

    
    

  • Achieving neat corners is essential for a professional presentation. To do this, first fold in and pull up on one of the unfolded sides so that the folded edge is vertical and aligned with the corner of the frame.   

    
    

  • Then, fold over the fabric as if you're making a hospital corner, and insert a staple right in the corner. You may also want to trim any excess fabric underneath the fold at this point. 

    
    

    

    How to fold the corner

    
    

  • Repeat this process on the remaining three corners. 

    
    
    
    

    

    Folding over the final corner

    
    
    
    

  • Finally, fold over the fabric on the last two edges and staple for a neat and professional finish.   

    
    

By following these steps, you'll create a perfectly stretched canvas that meets the high standards of professional artists. At HM Canvases, we are committed to providing you with the finest materials and support, from the frame to the final stroke.