Once my clients were satisfied with the composition of the Neverland Portrait painting idea ‘Doroteja in a Fishbowl’, I had to construct an oval-shaped canvas.
This post is in three parts.
Firstly, you can watch the video where I briefly describe in photographs what is the process of constructing an oval-shaped canvas.
The text below the video describes in more detail my knowledge and experience that I accumulated before taking all the steps in the process.
Lastly, in a brief, clear and visual manner, I write all the steps for building this type of canvas. If you wish, click here to jump to these steps straight away.
When we decided with Doroteja and her parents which details out of both painting versions were their favorites, next task was to decide how big the final oil on canvas painting should be. Luckily, for this I brought my own projector, which allowed us to quickly and easily adjust the size of the painting and see instantly what it would look like on their wall.
After our verdict, the following step was to construct the an oval frame and stretch on it the canvas. At the University in London, I had first hand experience with the help of technicians to build four canvases. However, when was working on this project, I had already graduated from university studies and lived in Lithuania, so I had to resolve a number of unexpected problems in order to perform this task. I had asked for help from many people – from my former teachers to my dad.
Canvas fabric
At this stage, I needed to find and buy a canvas of the right quality and size. It wasn’t as easy as I expected, but I learned a lot about it. You can read my collected knowledge of canvas fabrics for paintings in the following post.
When I bought the canvas for the painting, I travelled to my dad’s wood workshop to help me build the stretcher frame.
Oval stretcher frame
There are many ways to build an oval stretcher frame. In the past, I did it by nailing up eight wood pieces + one for reinforcements to save on material. My dad suggested me to simply cut out the whole frame with reinforcement from one sheet of wood since the wood at his place is very cheap.
Because a canvas would be tightly stretched over the frame and the fabric coated with primer would make it to shrink even more, there was a risk that the wooden stretcher frame would bend. To avoid this, we cut out and joined two layers into one frame, and we made the reinforcement in the form of a cross.
Edging of the stretcher frame
The wooden bar running along the edge of the frame is designed to raise the canvas above the wide boards of the frame so that the canvas stretches out like a drum. It is necessary part because this way prevents inner frame marks to show up during painting process. Let me explain this with examples.
The photo on the left shows the rectangular without canvas. The photo on the right, the canvas is already stretched over the wooden frame. The ‘skeleton’ if the stretcher frame shines through because the object is photographs with a window behind it. In this photo you can see how wide the wood bars of the frame are. When we make a mark on the corner with a flat charcoal stick, we can see that the edge of the stretcher frame is raised. The mark left by the charcoal also shows how the raised edge of the frame produces a drum effect. Thanks to that, no marks of the frame inner edges appear on the canvas when drawing or painting on it.
From this example we can understand why the raised edge of the stretcher frame is very important. But to make it on a round stretcher frame is quite difficult. The last time I built an oval painting in university, with the technician we decided not to put any edging, but instead make the stretcher frame itself wider and sand its inner edge. It was quite risky path, but I didn’t have any problems while painting. (View the painting here.)
As a result, I planned to build an oval stretcher frame for this painting without the elevated edge, but only sand the inner part of the frame. However, my dad encouraged me to look for solutions.
One idea was to fold the plastic strip around the frame because plastic is flexible. However, after trying to staple it, the plastic just broke, so I had to abandon this idea.
Another idea was to put a rope along the inner edge of the canvas, which could create a round edging on the painting. I didn’t like this idea, but for the sake of the experiment, we still did the test and the result came out just how I expected – the fabric stretches too tightly for the rope to remain at the edge of the frame.
The photo also shows how unevenly the linen fabric stretched out due to insufficient amount of stapling at the back of the frame. It was a good lesson, and it was good to discover it by performing only a test.
Finally, my dad found a sheet of wood in his workshop that was quite flexible. After cutting off a narrow strip, we tried to fold it around the oval frame and, to our success, the strip did not break.
Priming
Priming the canvas is required for several reasons.
First of all, unprimed linen fabric would absorb a lot of oil/acrylic paint into itself. After priming, the canvas gains a layer similar to that of paper. This way, the paint stays on the surface and does not absorb into the material.
Secondly, the primer layer protects the canvas from rotting. Oil paints especially accelerate the decomposition of the fabric.
Thirdly, with the help of primers, it is possible to create a specific surface texture of the painting. That depends on the type of primer and how many layers are applied and sanded. If the primer layer is thin, the canvas weaving texture will be visible on the surface of the painting. If primed and sanded many times, it is possible to reach a smooth surface as if it were out of an egg shell.
In my case, the linen canvas was quite rough and the weaving was not very dense, so the texture of the fabric was strongly defined. Since the composition of my painting contained small details (because I had to paint a full body portrait of a girl 15cm in size), I wanted a relatively smooth surface. However, it did not had to be particularly smooth either, because the painting was going to be quite large – a large painting is viewed from afar) and in many places it was colourful (the texture created with colours obliterates the rough texture of the fabric).
Steps I've taken to build an oval canvas
First we planned all the steps, carried out various tests, calculated the measurements, and only then we proceeded to the construction of the stretcher frame.
- I made a sketch of the frame, and my brother made a scheme on the computer software.
2. After ensuring that everything is programmed correctly, we turned on the machine (3 Axis CNC Router) to cut the frame from a sheet of wood.
3. After checking that the machine cut the form correctly (i.e. we did not make programming errors), we cut out a second form of the same size.
4. We combined both layers with an industrial stapler. Then we attached a flexible, thin and narrow strip of wood around the entire frame.
5. I polished the already finished frame with sandpaper, and then covered it with paint to protect the wood from moisture and rotting.
6. When using pliers and industrial stapler, I stretched the linen canvas tightly on the frame and stapled it densely on the back side of the canvas.
a. At first, I stretched and pinned the canvas on opposite edges.
b. After that, I stapled in between the gaps of the already existing staples, then in between those gaps, and so on.
7. After completing the stretching, I cut off the excess fabric.
8. I covered the front side of the canvas with a primer.
9. I waited for it to dry and then sanded the surface.
10. I did priming and sanding seven times until the surface became adequately smooth.
Here we’re ready for the colours, so we’re driving from the wood workshop to our studio. (‘We’ meaning me and the canvas haha)
