MAKE A CANVAS BOARD
Stretched canvas is usually cotton, however, the cheaper brands do not stretch well (the wedges penetrate the side walls before the canvas tightens). Canvas boards are not any heavier and they can be framed more easily, and take less room to store. Linen canvas is a finer weave but can only be purchased in bulk.
I make my own painting boards from 1/8" thick plywood and cotton canvas.
The plywood support
Purchase a 96” x 48” sheet of 1/8" thick plywood from a timber merchant that has a free cutting service. Enquire about the cutting service before you purchase the board; unless you have a motor vehicle that can transport a 48” wide sheet and you can cut your own. Have the cuts 1/8" less than nominal size, this will allow for the saw blade width and will allow for the thickness of the canvas cloth. DIY stores are convenient but very expensive, so shop around. My local supplier is Great Barr Sawmill, telephone: 0121 360 7373,
I use 4 sizes and have them cut 1/8" below nominal size, to allow for the thickness of canvas.
30” x 24” (Application - for landscapes) to get 6 pieces. Cut down the centre of the length to establish 2 pieces and the
24” dimension. Then cut each piece across the width at 30” intervals. There should be 2 pieces 24” x 6” scrapped but could
be saved for other projects.
24” x 20” (Application - for landscapes and group portrait) to get 8 pieces. Cut down the centre of the length to establish 2 pieces
and the 24” dimension. Then cut each piece across the width at 20” intervals. There should be 2 pieces 24” x 16” remaining.
Have these cut to the next canvas size down i.e. 20” x 16”. There should now be 2 pieces 16” x 4” scrapped but could be saved for other projects.
20” x 16” (This is the best size for portrait painting, and used for outside (en plein) applications)to get 14 pieces. Be careful with this one. First of all cut across the width at 20” intervals. This should give you 4 pieces 48” x 20”. Cut each one across width at 16” intervals i.e. a total of 12 pieces. The remaining piece should be 16” wide, so cut at 20” intervals. You now have 14 canvas pieces and one piece 16” x 8” scrapped but could be saved for other projects. I sawed my piece across the 8" width at 5" intervals to get 3 oil painting palettes.
16” x 12” (Good for 'En Plein' painting and colour sketching applications) to get 24 pieces. . Cut down the centre of the length to get
2 pieces 24” wide. Cut each one again down the length to establish 4 pieces and the 12” dimension. Cut each one across the width at 16” intervals. There should be no scrap.
If these quantities are too many per size, you could calculate the cut, to get a combination of these sizes, 12”, 16”, 24”, 30” can all be cut from
a 96” x 48" sheet with minimal scrap. Most timber merchants’ have off-cuts (but there may be more material scrap), so check costings, as this may be a more expensive alternative. I occasionally use sizes larger than the 4 given, and reinforce the plywood with bracing bars. I buy a
sheet of 8 mm thick plywood and have it cut into 12 mm wide strips. However, since most domestic living rooms are approximately the same size there would be a limited need to have paintings larger than 30" x 24".
I occasionally cut down a particular size for a specific application, so keep a few plywood supports in stock. Applying the canvas onto the new size.
The cotton canvas
You need to buy artist quality. My supplier is :-
Minerva Craft Centre, Minerva Fabrics Ltd, Atlas Road, Darwen, Lancashire BB3 3BY. Telephone number 01254708068. Website www.minervacrafts.com.
The construction process
Step 1 – lightly chamfer all edges on both sides of each plywood board with a rough file, rough sandpaper or wood planer. This will allow the canvas to be turned over the edge of the board more easily. Be careful not to overdo it.
Step 2 – cut the cloth 2” bigger than the board, on both dimensions.
Step 3 – coat one side of the board with PVA glue. When dry, turn the board over and coat the second side. Whilst still wet, coat the canvas sheet on one side.
Care Points- Check to ensure there is no unwanted material or wood shavings on the glued surfaces ( as you would with paper hanging).
Do not reduce the amount of overhang, as the cloth will shrink during drying.
Assemble the glued surfaces together, with a 1” canvas sheet overlap on all sides of the board. A paste table is useful for this process.
Working from the centre, squeeze the glued surfaces together removing any bubbles (as you would with paper hanging). Prepare two constructions, then by placing together with the canvas material facing each other. Add wood clamps or bull dog clips around the edges to press both assemblies together. This will ensure that the glued canvas/board surfaces remain in contact. Leave for about 2 days, by which time the bonding process should be complete.
Step 4 – Glue and turn over each edge of the assembly. Masking tape should now keep the 1” strips in place until bonded to the board. Once dry, trim the canvas edges and corners to tidy up the assemblies. Check and glue any detached canvas material, and allow to dry.
Step 5 – Coat the canvas surface with household emulsion, which is water based. Do not use undercoat or gloss paint as these are both oil based. Repeat this a further 2 times, allowing to dry. After completing the third coat, lightly sand the canvas surface, to smooth and remove any unwanted debris.
Step 6 (Optional) – On the reverse side you could coat the plywood surface with a light grey coloured emulsion. This would reduce any tendency for the plywood to warp and will give a more professional finish.