In order to paint you need the appropriate surface to paint on. Here I will explain how to prepare canvas for oil painting.
There are several different materials to use as a canvas. Most commonly used are cotton and linen fabrics. Cotton canvas is affordable and it stretches very easily and if prepared properly it will last a long time but it’s considered too flexible for large paintings. Linen canvas is strong and durable if you want your painting to last you should use linen canvas which is less prone to expansion or contraction due to moisture.
Stretching The Canvas
The canvas is stretched on the frame. Make sure that the frame is built of dried wood and that the inner edges of the frame are cut in a downward angle so that the canvas lays only on outer edges of the frame. When stretching the canvas make sure that the canvas is bigger than the frame for at least 3cm on each side. Place the canvas on the clean flat surface and then place the frame on top of it.
Attach the canvas to the frame on every four sides with a nail or a staple gun making sure that the vertical and horizontal thread between each two attached parts makes exact cross whose lines are parallel to the sides of the frame. Attach one side of the canvas to the frame using nails or staple gun then do the same with the opposite side parallel to the first one. When attaching the last two sides stretch the canvas as much as you can so you get a nice firm surface to paint on. Leave the angles for the end.
Sizing And Ground
The canvas is now prepared for sizing. Sizing is applied to protect the canvas from acid in oil paints that make the canvas deteriorate. For sizing, you use a weak solution of animal glue which you apply with a brush. Sizing can come in granules which you need to soak first to soften them, then you heat them to melt into liquid and apply with a large soft brush. That is rabbit skin glue sizing. You can also use already prepared sizing which comes in form of thick liquid and you can purchase it in any art supply store. On top of the sizing goes ground which additionally protects the canvas and gives you the surface to paint on.
Ground prevents the colour from penetrating the canvas and the most commonly used colour of the ground is white, but it comes in other colours too. The white colour of the ground makes the colours you paint with look brighter and stronger. The most common ground is Gesso which can be made or purchased in varying levels of consistency-from cream to a paste.
Gesso should be applied in at least two thin layers. Because it dries rapidly it must be quickly applied in smooth even strokes in one direction with a large brush. You should let it dry for at least one hour before applying the second layer. When the first layer is dry use fine sandpaper to smooth it then wipe the surface with a dry cloth to remove residue. The second layer is applied the same as first but in opposite direction. Between applications make sure to rinse the brush thoroughly because gesso cannot be removed once it’s dried. Make sure you apply sizing and ground on the sides of the canvas to protect it from deteriorating.
Now your canvas is ready for painting. I give you the basics, it is you who will make the magic with it.
Most of you might find all of this a bit confusing and difficult to do so my advice will be to at first buy already prepared cotton canvas which is much cheaper than linen one and start painting. It is always better to prepare your own canvas because you can make it fit your needs the best, but already prepared ones can also be very good for beginners.
If you have any questions concerning the subject please feel free to leave a comment or contact me and ill make sure to answer them.