For rough scaling of simple 2-D objects, you can probably get by with only measuring the width and height of the object. [1] X Research source It’ll be helpful when you start drawing the scaled image if the perimeter is broken up into segments, like the top, bottom, and sides. [2] X Research source You may be able to break up the perimeter into small, regular shapes, like squares and triangles. These segments can be added together to find the perimeter.
When scaling down images that are especially large, expect the second number in the ratio to also be large. A 1:5000 ratio might be used to fit a building-sized object on a single sheet of paper. Enlarge small images by increasing the first number of your ratio in small increments. A 2:1 ratio will be double the size of the original, a 4:1 ratio will be quadruple, and so on.
Some ratios may be irregular, like 5:7. All this means is that for every 5 units of distance in the scaled drawing, you’ll have 7 units of distance in the original. [4] X Research source For example, if scaling down with a 1:2 ratio, a length of 4 inches (10 cm) would become 2 inches (5. 1 cm) because 4 ÷ 2 = 2. When scaling up with a 2:1 ratio, a length of 4 inches (10 cm) would become 8 inches (20 cm) because 4 x 2 = 8.
If your drawing doesn’t have a suitable straight segment, one that is mostly straight might work just as well. If your image is highly irregular, try drawing the perimeter from the top down or bottom up.
Check your converted measurements against the drawn lines of your scaled image as you go along. Erase and adjust lengths as necessary. It may help to draw a grid over the original drawing and then putting another grid on the larger piece of paper to match the ratio you chose. That way, you can easily reference where something is supposed to be. [5] X Expert Source Kelly MedfordProfessional Artist Expert Interview. 10 March 2021
When you finish drawing, check to make sure that all lines of the drawn image match your converted scaled measurements.
For the highest quality and most accurate scaling, prioritize using a design program, like Photoshop or GIMP. [6] X Research source
Some programs may use different wording for these options. Feel free to play with settings in the “Size” menu to see how changes affect the image. If you have difficulty finding “Size and Position” try looking for scaling options in the properties of the image or in an image formatting menu. [8] X Research source
When the percentage exceeds 100%, the image will become enlarged. Enlarging images may sometimes cause graininess or pixelation, especially with low-resolution images. [9] X Research source
