 |
| (pic from alisaburke.blogspot.com) |
Stretching a painting on canvas is quite easy when you follow some simple steps. When a painting has been done on cheap canvas or some other poor material it is best to seek professional picture framing advice because stretching some pictures is challenging and awkward. In this article you will learn about how to stretch a canvas painting, how to choose and cut a stretcher frame and how to finish off the stretched painting so that you can hang it for display.
Artists have chosen various surfaces for painting on over the centuries ranging from raw plaster walls, wooden panels,paper and fabrics. When an artist paints on fabrics it is usual to prepare the canvas first with a primer. The priming layers are very important when it comes to providing not only the right surface for accepting paint but also to provide a long-lasting support that will not deteriorate easily.
As a quick overview to help you understand the nature of a painting on canvas the steps taken to prepare a traditional canvas are as follows.
The first step was to choose a suitable fabric. Artists preferred to use linen over other fabrics due to its strong fiberous construction and stability. Cotton canvas was a poor second choice when linen was unavailable. the fabric was traditionally coated with a sizing coat made from animal glue or pearl glue. These glues are made from gelatinous materials extracted from rabbit skins and other animal products. The aim of the sizing was to coat each and every strand of the fabric with a layer that when dry would seal and protect the fabric.
The second step was to make a mixture from rabbit skin glue mixed with dead plaster and whiting or chalk. Dead plaster is made by stirring plaster of Paris with water for about half an hour. When you mix plaster beyond its setting time you change the crystalline structure preventing it from drying out and setting like traditional plaster, hence dead plaster. The dead plaster has a different structure than the whiting that is added to the glue to make the artist's gesso.
The warmed mixture of glue, whiting and dead plaster was then applied to the surface of the pre-sized fabric. Several coats are applied in successive and alternate layers building up a smooth toothy surface that will accept paint. The trick to applying the gesso was to apply a layer and then wait for it to lose its glossy appearance before you applied the next layer. After several layers the canvas was set aside to dry.
Artists would often do this preparation to the fabric after it had been stretched over a supporting frame.
The fabric had first been stretched over a tapered bar called a stretcher bar.
It is important when stretching paintings that you choose a suitable stretcher bar that either has a rounded raised lip or a tapered bevelled profile.
If you just use a flat piece of timber for your stretcher frame you will create problems in the painting later by causing an impression line where the timber touches the back of the picture.
Modern artists often buy pre-primed artist canvas and linen that has a synthetic gesso coating on its surface. It is even acceptable from a conservation standpoint to use synthetic polyester fabrics rather than linen or canvas. These synthetics are more stable and durable than some of the organic fabrics.
One big problem is with developing countries where artists are unable to obtain quality supports. I often encounter paintings that have been done on cotton bed sheets, hessian bags and tarpaulins. These each present different challenges when trying to make them presentable.
Basically to stretch a canvas that has already been painted on it is necessary to determine whether the fixtures or staples you will use will go on the side or the back of the stretcher first.
The process of stretching a canvas involves either cutting and joining some lengths of stretcher bars into a frame or buying pre-cut slotted stretcher pieces from an art store.
The slotted corners are made with a sliding tenon joint that allows you to tension the canvas further after stretching over the bars. There are several methods of achieving adjustable corners to allow further tension to be applied to the canvas by expanding the corners..
NOTE: If you use a slotted variety of stretcher bar ensure you have it squared up before you stretch your canvas otherwise the painting will be crooked. Measure the diagonals to check squareness.If the frame is a parallel and the diagonal equal then it is square.
The painting is then positioned over the stretcher frame with the lip or tapered side of the stretcher touching the back of the canvas.
You then work gradually from the centre towards the corners using a staple gun or small tacks pulling the canvas as you go.
The trick is to work gradually on opposite and then adjacent sides only putting a couple of tacks in at a time.
Stretching pliers are a useful bit of kit for the job of stretching. They consist of broad- faced pliers with either a toothy grip or a rubber strip to grip the canvas. They are used to lever the canvas around the stretcher bar, applying tension, whilst you tack or staple the canvas to the frame.
Sometimes the staples or tacks can be on the back if you want to see the sides of the painting without putting an outer frame on it.
When you get to the corners you neatly fold the corners over using a Monroe corner where the two sides overlap a central tongue that is not fixed. The reason for this is if you wish to re-tension the canvas the corner must allow some expansion for the canvas otherwise it will tear.
Usually you would either then frame the painting or at the very least apply a dust cover of some foam board or other covering. The covering is important in the long-term to prevent dust building up on the back of the painting which in turn traps moisture and then eventually goes mouldy.
You can then fix some D rings and wire to hang the painting up.
Professional framers prefer to frame canvasses so they are not exposed around the edges. They also like to put the hanging device on the outer frame rather than the stretcher because hanging from the stretcher can cause bowing which then causes a ripple in the painting.
Hopefully this article has shed some light on the requirements and techniques to choose when stretching your paintings.
David Schummy, owner of Fix-a-Frame, is a qualified picture framer from Brisbane, Australia.
David authored 16 of the 22 modules the Australian Government uses to train picture framers. He has taught picture framing to professionals and hobby framers since 1991.
His latest DVD "Seven Secrets to Making Picture Frames" is available from http://www.fixaframe.com.au
Visit http://www.endurart.com for your Free E-Book "The 10 Questions To Ask All Picture Framers"
Article Source: http://EzineArticles.com/?expert=David_A_Schummy
Artist canvas is a woven material that is typically used for paintings; It is stretched over support to create an even surface. Canvases are made from cotton or linen and often pulled across wooden frames. There are several types of canvas, and some are better than others. One type is stretched linen canvas designed for professional artists.
ReplyDelete