HOW TO TENSION CANVAS ON A FRAME
The stretcher serves as the basis for stretching the canvas. Subframes are of 2 types: modular (prefabricated, wedge) and deaf.
Modular (prefabricated, wedge) subframes can be bought in almost all art stores. They are sold in racks of 2 pieces (in increments of 5 cm in length) and cost a little more than deaf subframes.
Modular subframes have a huge advantage – their angles are not rigidly fixed and when the picture is sagging, the problem can be easily and quickly fixed at home – you just need to knock out the wedges (Figure No. 6). This must be done very carefully so as not to spoil the canvas with a hammer and not to drag it.
In deaf subframes, the corners are rigidly connected and if the canvas sags, it will have to be pulled. The banner must be done only by a specialist!
As a rule, a subframe 1.8 cm thick is used for a medium-sized picture, and 3 cm for a gallery stretch.
FRAME AND SAFETY OF PICTURE
Poor subframe negatively affects the safety of painting. Pictures of modern painters very often have poor stretchers. Unfortunately, not all artists attach great importance to the quality of the stretcher.
Defects of the stretcher do not allow the canvas to be properly pulled over it, which ultimately leads to the destruction of the soil and the painting layer of the picture.
A quality stretcher is the basis of the long-term preservation of the painting.
Consider the main defects of the subframe
The blind connection of the corners, which makes it impossible to adjust the tension of the canvas, which causes the deformation of the canvas and its sagging.
Artists beat plywood triangles onto the “dead” corners of a stretcher, which make the stretcher even more rigid and motionless.
The absence of a cross or bar – for paintings of large size. A subframe with a cross or crossbar does not warp and the corners remain straight.
The absence of bevels on the inner sides of the subframe, which causes creases and screes of the paint layer, which are inevitable from vibration of the canvas with subframes that do not have these bevels.
It is better to choose a stretcher, which has rounded off all places of possible contact with the canvas (all sides on the front of the stretcher), so you will avoid serious damage to the canvas during transportation.
Unstable subframe, which, when pulling the canvas, gives a skew.
Step-like, loose connection of the strips in the corners and on the cross. With this defect, the canvas is deformed, creases and screes of the paint layer appear and it is impossible to tightly connect the picture with the frame.
The subframe is made carelessly from raw wood, as a result of which, after a rather short period of time, the subframe will “lead” and it will have to be replaced (in some cases, the frame has to be replaced).
The subframe is made of wood with knots. Even a well-made stretcher, on which there are knots, will surely “lead” over time and will have to be replaced.
Subframe with beetle grinder. Thanks to the activity of these insects, the tree decays, turning into dust.
The subframe is infected with mold.
To stretch the canvas you will need a stapler with staples (Figure No. 1), a special tool for stretching paintings (Figure No. 2), a tape measure and a hammer.
Never entrust stretching or hauling paintings to random persons: carpenters, joiners, etc. An old restorer must pull the old painting!
It is very important for proper canvas tension to evenly stretch the canvas and feel the limit of tension.
INCOMPLETE TENSION LEADS TO ADVERSE EFFECTS:
The formation of micro-fractures during shaking from hammer blows (this is mainly important for old painting).
If the picture is too tightly stretched – the appearance of craquelure during self-tensioning of the picture under the influence of atmospheric vibrations.
If the picture is stretched too weakly and unevenly – sagging and creasing.
The appearance of cracks in the paint layer and soil along the edges of the picture.
CANVAS TENSION FORCE
The raw canvas is not pulled much, because during the primer, it will stretch significantly. The final touch will be stretching the primed canvas by knocking down wedges in the corners. For a deaf stretcher, it is advisable to use a primed canvas. It needs to be pulled tight like a drum.
It is strongly not recommended to stretch the canvas in the wet state, since the threads of such a canvas are deformed irrevocably. Cotton canvases or canvas mixed with cotton suffer from wet pulling multiple times more. Wetting the canvas has Soviet roots when our artist dealt with hard and brittle canvases. Such canvases were so inconvenient in the preparatory work that they were invented to “moisten” to invest stretching on a stretcher. Then, as in Europe, such a practice has never happened.
CANVAS TENSION ON MODULAR FRAME
Measure the diagonals of the subframe, they must be the same !!! Fix the corners with a stapler (2 brackets per angle).
Place the picture of the picture on the stretcher exactly horizontally. If you simply do not have a primed canvas, it is important to arrange it so that the direction of the canvas threads is parallel to the edges of the subframe.