How to Preserve a Chalk Sketch

Chalk, better known to artists as soft, hard or oil pastels, is a very flexible medium for artists interested in depicting fine gradations of light and color in their work. Pastels lend themselves very well to the Impressionist and Post Impressionist techniques which made Pissaro, Cezanne, Monet and many other 19th Century artists famous. Block style pastel chalks are easy to feather, blend, and burnish, but they are also easy to muddy. Loose chalk dust can settle in unwanted places on your drawing and smudge or smear, destroying the effect you just spent hours painstakingly creating.Sealing a chalk sketch helps preserve strokes and marks while maintaining blending as you intended it to be.

Things You'll Need

• Chalk sketch with at least one layer of pastel applied
• Sheet of cardboard, larger than your drawing
• Can of quick drying clear spray acrylic
• Large box fan or overhead ventilation system

Instructions

1. Lay your drawing on a sheet of cardboard to protect it against overspray. Be sure you have adequate ventilation by turning on a large box fan pointing out the nearest window or outside door, unless you have an overhead ventilation system. If you are able to smell fumes when you begin spraying the acrylic, you do not have adequate ventilation. If necessary, do all spraying outside or with all doors and windows wide open.

2. Shake clear acrylic vigorously for three to five minutes. You should hear a clacking noise from the little ball inside the can. The propellant separates when spray paint is stored. Inadequate mixing can result in drips and streaks during application. Spray one or two short bursts on a separate sheet of paper to be sure you will get good coverage. Move wrist in short, quick top to bottom strokes, holding down button on can and releasing, just as if you were drawing short hatch marks on your paper.

3. Once you have practiced short strokes and quick bursts of the acrylic spray, check your drawing. Blow gently on it to remove any last traces of chalk dust. Shake paper carefully to ensure everything falls away from your drawing.Beginning with a short burst of acrylic, and using the quick up and down wrist motion you just practiced, begin applying acrylic to your sketch. Work from right to left and from bottom to top. Do not hold the button down and keep spraying. Be sure to release the button between each burst of acrylic. Shake can vigorously every fourth or fifth burst to keep acrylic and propellant well mixed.

4. Once the entire drawing has been given a coat of acrylic, allow to dry. Drawing should be stored horizontally while drying to prevent rip from forming.Do not apply a second coat before drawing is completely dry.If you intend to continue drawing additional layers in other colors, wait at least 24 hours before you proceed. If you are not going to add any more details to your drawing, give the entire piece a second coat of acrylic. Be sure to work in short bursts.

5. For additional protection, place pastel chalk drawings in glass frames to prevent rub off.

Tips & Warnings

• Shake can vigorously until you can hear the clacking of the ball inside the can.

• Blow dust off drawing before applying acrylic.

• Use a piece of cardboard as a spray background to prevent overspray.

• Work outdoors of necessary, to avoid fumes.

• Be sure to use adequate ventilation. If you can smell fumes, you do not have adequate ventilation.