If you’re aiming to have a realistic painting, with accurate perspective, then it’s crucial to get the angles of the elements in the painting accurate. Not only the angles of how the objects lie in relation to each other, but also of the items themselves.
Here are various ways to measure angles:
• Hold your brush or a pencil up vertically then judge the angle by thinking of the small hand on a clock. Does the edge go out from the vertical at four o'clock or five o'clock? Or, even more accurately, by thinking of the large hand on a clock – does the edge go out at five minutes past twelve or three minutes past?
• Line a pencil or brush up with the angle then, holding it at the same angle, move it down to your painting to check the angle you’ve got.
• If you find that you move the brush when doing this, try using two pencils. Line them up against two edges in the object so that they overlap. Now grasp them firmly where they overlap and bring them down to your painting to check the angle.
• Open a pair of compasses until the arms match the angle, then move the compass across to your painting to compare. The advantage of a compass is that it'll probably be stiff enough not to close up as you move it.
• Make yourself a plumbline from a piece of string with a weight such as a large bead or small fishing weight at the end. Hold the end of the string in your fingers and gravity will provide you with a vertical line against which you can judge angles.
• Get a school protractor and drill a hole through the 'centre' spot. Attach a plumb line to this and use it to measure angles from the vertical.
• One that’s not for youngsters: Open a pair of scissors until the blades match the angle. (Let's face it, most adult artists are more likely to have a pair of scissors lying around than a pair of compasses.)
Tips:
• As you become more experienced, so you’ll be able to rely more and more on your ‘eye’ and have to measure less.
• When something in a painting just isn’t working, go back and systematically check all the angles.
