Proportional dividers allow architects and artists to transfer different measurements onto paper while keeping the same proportions. This ensures that drawings stay to scale to each other. Use proportional dividers for your next art project or to aid you with your sketches to help you create a realistic rendering. Use the sliding thumb nut located in the center of the proportional dividers to pick the scale you want to draw in and begin sketching your accurately scaled illustration.
Things You'll Need
Twist the thumb nut in the center of the proportional divider to the left to loosen. Slide the nut up and down to adjust the scale. Numbers on the side of the proportional divider, just above the thumb nut, indicate the different scales. Most proportional dividers have a scale range of 1:1 to 1:10.
Hold the proportional divider with one hand and extend your arm out directly in front of you. Next, put the item you want to draw within view of the small opening of the proportional divider. Adjust the dividers with one hand until the two needle points on the short end accurately reflect the dimensions of the object from your vantage point.
Bring the proportional dividers back to your drawing paper or canvas and use a pencil to mark the length created by the larger opening of the divider. Since the proportional divider operates on a pivot, the small opening and the large opening are proportional to each other. Thus, even though you measured the object with the small opening, the large opening transfers the measurement to a larger scale.
Continue measuring objects with the small opening of the proportional dividers and transferring the scaled measurement to the drawing paper. Use these measurements to draw a proportional illustration.
Gently place the proportional dividers against the drawing paper or canvass to prevent moving the legs. Even the slightest movement creates inaccuracies in the scale. Always measure objects with a proportional divider with your arm fully extended to keep your measuring method consistent.