Hello to all my Facebook artist friends and those who somehow managed to find me on these pages. Periodically,
I post topics of interest to artists from elementary to advanced levels. On this occasion I am posting three videos about surfaces
to paint on, the procedure for stretching a canvas, gluing and priming, as I have noticed that some of the new members in our
Facebook Group have shown interest in this topic.
You never know in advance if the painting you are working on is going to turn out to be
very good or even excellent. If you want your painting to last many years, you must take the appropriate measures. You have two alternatives to prepare the canvas
after stretching it on wooden stretchers. If you decide to go with an oil primer, the canvas should first be protected by applying some type of glue, such as
rabbit glue. Let it dry for several hours before applying the primer. Oil primer takes at least a month to dry.
If you decide on the second alternative, acrylic Gesso, it can be applied directly to the canvas. Gesso dries quite quickly and
should be sanded down with a 150 grit sandpaper between coats of Gesso. I have paintings that have lasted almost 50 years with only two coats of Gesso.
Cover all fibers of the canvas with Gesso without leaving any gaps. The back of the canvas can be covered with paper
or cardboard to prevent the entry of insects.
Video: STRETCHING A LARGE CANVAS.
Video: MATERIALS FOR STRETCHING THE CANVAS.
Video: SURFACES TO PAINT ON.
Video: BUILDING A CANVAS PAD.
Rabbit Skin Glue
The rabbit skin glue is made by boiling animal tissue. This glue can be purchased in powdered
form or in larger chunks. The preparation with the correct proportion of water should be heated in a double boiler, just below the boiling point. Too much heat results
in a product with reduced adhesive qualities.
Manufacturers of rabbit, cow and horse skin glue recommend dissolving it at 60-63C (140-145F).
Rabbit skin glue is only suitable for use under oil paint. Acrylic-based mediums will come off a canvas prepared with rabbit skin
glue and are therefore not appropriate.
HOME RECIPES TO MAKE GESSO
Gesso protects the fibers of the canvas, provides a good surface to work on, and gives some flex so the canvas won't crack if rolled.
3 parts cornstarch
3 parts baking soda
1 part glue
1 part white acrylic paint or black acrylic paint
2-3 parts of water
Mix the cornstarch and baking soda until smooth. Then add your glue and acrylic paint and mix everything up really well. Finally, add water a little at a time until you have the right consistency.
With white school glue
1/2 cup (4 oz) school glue
3 cups (24 oz) talcum powder
2 ounces of black or white acrylic paint
water to desired consistency
Add school glue, talcum powder, and acrylic paint to a container and mix well. Finally, add water a little at a time until you get the desired consistency.
With powdered chalk
250 grams (9 ounces) of water
125 grams (4 1/2 oz) white school glue
750 grams of powdered chalk (marble dust, calcium carbonate or calcium gypsum/sulphate)
120 ml of white acrylic paint or black acrylic paint
First, mix the glue and water until fully mixed. Then, add the powdered chalk slowly to the glue and water mixture until everything is
fully integrated. Make sure there are no lumps. Add the white or black acrylic paint to the previous mix.
Clear gesso with cornstarch
4 parts white school glue
2 parts water
1 part cornstarch
First, mix the cornstarch with water, (this prevents lumps from forming).
Then, add the glue to the previous mixture and mix very well.
Years ago I used a manual staple gun to staple the canvas to the stretchers. My effort to press the trigger and shoot
the staples became greater as years passed. For that reason I ended up buying an electric staple gun. Of course, when using it, precautions should be taken to avoid accidents that may
cause a serious injury to your body or persons nearby. It does not require much effort and in addition to staples, it can also shoot small nails.
However, both staple guns seldom penetrate the hard wood of the stretchers completely. So, a hammer is needed to drive in the staples fully.
Staples should not be hammered too hard as the corners of the stretchers may be thrown out of square in the process.