Oil and acrylic paintings differ significantly from each other. It is easy to see the differences even with the naked eye. This is justified by the fundamental difference between the material with which the canvas is painted and the technique of preparing the canvas. For oil painting, paints exclusively based on vegetable oils are used, since these oils are the main binding component. It is worth noting that canvas primed for painting is more suitable for creating an oil painting than acrylic, since acrylic paints are water-based. There are several basic techniques for applying a primer. Both acrylic and oil paints. In addition, the canvas itself can be made of various materials.
Factory canvas primed for painting
For novice artists or those who do not want to spend time preparing a canvas for painting, materials already prepared for work are sold. For oil paintings, a special canvas is sold, primed, in a roll. It does not need to be glued or sanded, you can immediately after purchasestart drawing. This is done quite quickly and simply, the procedure does not require special skills or abilities. Also on sale you can find a canvas primed with a contour, along which in the future the remains of the canvas are either cut off or used to fix the finished picture in a frame. Prepared canvases for work are sold not only for oil painting, but also for acrylic. In case fabric is replaced with cardboard, since acrylic paints are water based and look much better and more effective on paper than on any other materials, canvas primed on cardboard is used.
What should the canvas look like?
The main criterion that should be present in the canvas for painting with oil paints is its elasticity. During the application of the primer under the brush, a pleasant springy effect should occur, due to which the strokes will be more expressive, and the application process itself will be much more energetic. It is best to use linen or hemp as a base material, since cotton, viscose or any other types of fabrics do not interact well with the primer due to their grainy texture. First, study work should be done on canvases with medium threads, but if you plan to paint a large picture, you should use coarse-grained types.
The basis for painting with acrylic paints should be selected more carefully and responsibly, since the paints themselves are very specific. This is justified by the fact that, thanks to the water base, suchmaterials require special thinners. The main advantage of acrylic is that the finished painting from this material does not turn yellow over time, and the paints themselves are hypoallergenic. Due to its structure, acrylic is best suited for cardboard, as paper has the ability to absorb excess water. However, ordinary cardboard is not suitable for painting, usually Sonnet brand cardboard is used for writing pictures.
Before you start
When choosing a material, it is very important to know how to properly prime the canvas so that the material lays down with the highest quality. If, nevertheless, a novice artist wants to master all the basics of painting and decides to prime on his own, he must take into account that this is a very long and laborious process. In addition to a lot of time, this will also require quite a lot of primer material, therefore, if the budget of the picture is relatively small, then it is better to buy a ready-made primed base, since a decent amount will be required to purchase material for self-priming. Here it is very important to understand the following point. When buying a cheaper and not very high-quality soil, there is a risk of spoiling the whole picture completely, since low-quality material will be at its base.
Priming a canvas at home is possible, and this option has several advantages over ready-made, factory primer. First of all, the artist himself can choose the shade that he wants to see as a base, you can mix several tones at the same time and eventually getsomething unique and original. In addition to shades, there are no restrictions on the shape of the canvas of the future picture, it can be adjusted at your discretion. Another positive point is the layer of soil application. It is also controlled directly by the artist and selected in accordance with the necessary artistic goals. The main signs of the correct application and quality of the primer are:
- Applied over a primer, the paint dries evenly.
- The primer completely covers all holes and minor material defects.
- With its help, the desired texture is created, which can be perfectly smooth, with the preservation of the texture, or with various visual effects.
- Primer provides protection from ink directly on the material.
- Using a primer, the surface of the painting should have maximum adhesion to any paints or other art materials used.
- Quality primer provides guaranteed resistance to moisture. It also has antiseptic properties.
If the fabric is treated with a quality primer, it will retain good elasticity for many years.
How to prime canvas under oil
If you decide to figure out how to prime the canvas, before you start applying the primer under the oil, it must first be fixed on a stretcher and prepared. How to stretch the canvas on a stretcher can be found below in the article. If the application of soilperformed independently, the material should be as dense as possible, with a minimum number of various defects.
First of all, before applying the first layer, it is necessary to moisten the canvas a little so that moisture does not appear on the wrong side of the canvas. Moisture will give the fibers expansion, due to which the glue will practically not seep during sizing. Also, if there are small knots or irregularities, you can sand the stretched canvas with pumice stone.
Applying glue will protect the canvas from impregnation with oil from paints. However, do not apply glue too thick, the canvas must retain elasticity and natural texture. But at the same time, holes and protrusions should be absent. Usually the glue is applied in two stages in several thin layers with intermediate drying.
The first stage of applying the glue is the most important and responsible, since it is necessary that a thin protective film is formed, and at the same time the glue itself does not seep through the canvas. For this, liquid glue at room temperature is most often used, due to which uniform distribution is achieved throughout the web. And fast, secure fastening. If the surface texture is sufficiently rough, the adhesive should be of a thicker, jelly-like consistency. When applying such glue to the canvas, do not press so that it is not completely saturated. You should also avoid repeated smears in the same area. If the adhesive solution is liquid, it must be applied very quickly so that no excess occurs. After the first layer, you need to dry and sand the canvas. Then apply a couple morethin layers of glue, drying and grinding in between, and only after the sizing becomes uniform and the gaps between the fibers disappear, you can start applying the primer. To apply thick glue, you need to use a palette knife or spatula, and for a liquid solution - hard and wide brushes.
How should canvas be dried and sanded?
It is necessary to dry after each application of primer to the canvas. If you know how to prime the canvas, drying shouldn't take too long. The main thing is not to violate the generally accepted technology, so as not to degrade the quality of the base. Depending on which mixture is used, the drying time may be different. So, for example, adhesive primers take about five days to dry, and emulsions - up to two weeks, oil formulations dry the longest - from 2 to 10 months. It is very important that the drying of the soil is uniform. And it was done at room temperature. It is strictly forbidden to dry the soil in the sun, near the battery or in a draft.
After you have finished priming the canvas, the primer has dried, it is necessary to sand the canvas before applying the final coat, as this removes various defects from the canvas and improves adhesion. Grinding is carried out using fine-grained sandpaper or pumice stone. The sanding itself must be as careful as possible to avoid damaging the texture of the soil. The final layer of soil is usually untreated. Only if there is a need to increase the adhesion of the paint.
What is appliedprimer?
Applying a primer is carried out only in a thin layer. And only with a brush or palette knife. The principle of applying a primer is exactly the same as gluing a canvas. In order for the adhesion of the soil to the paint to be as effective as possible, the tint is added to the soil in stages, in each new layer its content increases. Thanks to this technology, the surface of the canvas will become as elastic as possible, resistant to moisture and temperature fluctuations, as well as other external influences.
How convenient are canvases with ready-made sizing and primer?
In every specialized art store you can buy canvases already prepared for painting, for example, a primed canvas in a roll, for oil painting. Its acquisition greatly facilitates the work of the master and significantly saves his time. Since it is oil primers that dry the longest. However, there is also a primed canvas on cardboard for sale, for acrylic writing. Such canvases will not only save time spent on the primer, but also save the artist from various unpleasant nuances, such as the flow of the canvas during impregnation with glue or other moments. This is precisely the advantage of factory bases with a primer. They significantly save time, effort and, of course, money spent on preparatory materials. The most popular among canvases for painting with acrylics is the primed canvas on cardboard "Sonnet".
At home
For oil primer, you canuse a gelatin-based primer prepared at home on your own. This primer is quite easy to apply and relatively inexpensive. It is suitable for processing a dense and rough canvas, since it can be either liquid or half-frozen. Gelatin primer for sizing may consist of components such as glycerin or honey, directly gelatin, white or chalk and water. Each layer of such soil dries out in about 12 hours. The main thing is to carefully dilute the main components (honey and gelatin) in a water bath during cooking so as not to overheat them.
You can also use glue primer. It is very convenient, as it dries quickly, but there are also negative aspects to consider. During painting, this primer often sucks in the binding components of the oil paint. Also, this soil is very susceptible to moisture and dampness. Another problem is the increased stiffness of the web after processing. And if you use adhesive primer with a softener, after a while the canvas may begin to rot. Most artists prefer casein primers or polyvinyl alcohol with zinc or titanium white added.
Unlike glue, oil primer is resistant to high humidity and does not absorb paint binders, however, it also has some drawbacks. It dries for a very long time and after a while begins to turn yellow, as a result of which the image gradually darkens. Acrylic canvases are much easier to prime. Since they are well suited to almost any type of soil.
How to prime the canvas underacrylic: preparation
Primers based on acrylic itself are most often used as a primer for acrylic painting. They are a special mixture with the same binder as the paint itself - an acrylic polymer emulsion. The composition of such primers also includes barite with magnesium and calcium carbonate, which create a certain texture of the primer. If the picture is painted with body paint, priming is not necessary at all. The only thing that is required is to form a continuous solid film, on which paint will then be applied. This is necessary to protect against soaking, since acrylic paints are water-based, and various types of cardboard are used for the canvas. For acrylic works, as well as for oil paintings, there is a special primed canvas on cardboard with an outline. The contour will later be needed to frame the picture.
Features of applying primer under acrylic
You can apply a primer on a canvas for acrylic painting vertically or horizontally. Applying a primer on a horizontally located surface is carried out as follows: a primer is poured onto a lying canvas, after which a quick, accurate distribution of the mass around the entire perimeter begins with a scraper or squeegee, you can also use a rubber spatula. The layer must be thin. It is very important not to use tools containing soft black rubber to spread the primer over the surface of the blade, as this will cause the blade toget dirty with black stains and hopelessly deteriorate.
If you find out after you have primed the canvas that the consistency of the primer is rather runny, it is best to avoid applying vertically as this can cause a number of specific problems such as streaks and uneven application. Although many professionals use this method. Indeed, with its help, the primer of the canvas is carried out much faster than the usual application of primer with a brush.
If the canvas is sufficiently hard and rough, apply primer only with a brush. Given the degree of absorption, the application is carried out in several layers, but not less than two. The first layer is usually diluted with water. If the canvas is fairly large, you can use a sprayer for an even and smooth primer.
If a primer with a strong absorbent effect, such as wood fiber board, is used as a primer for acrylic painting, you can add an acrylic glossy agent applied in one thin layer to it. Immediately before application, it must be diluted with water. This is necessary in order to reduce the level of porosity of the primer to an acceptable level. When applying a primer to a surface with an increased level of absorption, which has not previously been glued, the binder components of the material are completely absorbed into the canvas. Because of this, a “grain-powder” effect will appear on the surface. Recently, ready-made primed canvas on Brauberg cardboard has appeared on sale, especially for acrylic painting.
Whatwhat next? You need to figure out how to stretch the primed canvas on a stretcher. To fix the canvas on a stretcher, you will need to do the following: spread the canvas on the work surface and put a frame on top of it. It is very important that the fibers of the canvas are in the same direction as the lines of the frame. This moment must not be missed. If the fabric lies at an angle, over time, the deformation of the frame and the bending of the edges of the canvas will begin. It is necessary to take the nearest long edge and tuck it into the inside of the stretcher. Then, using a stapler, fix with three brackets. At the edges of the stretcher, the canvas is fixed at the final stage. After fixing one side, it is necessary to unfold the canvas and, having pulled it well, perform the same procedure. Staples must be started from the middle to the edges, otherwise the canvas will come out skewed. And will sag in the center. If a non-primed canvas is fixed, it should be slightly moistened with water before starting the process, you can use a spray gun. It is necessary to moisten the inside. This is done so that after the water dries, a denser stretch of the canvas is formed. It is best to spray with water after securing the long sides of the canvas to the stretcher.
