Last week's post sparked some very interesting conversation - both on Ctrl+Paint and DeviantArt - and I'd like to devote this week to weighing in on the topic. We'll explore visual measuring, grids, rulers, and tracing; are they methods of 'cheating', or simply tools?
To begin with, I'll say that the idea of 'cheating' in art is very misleading. If anyone is cheated by using a grid, it's the artist themselves. Unless you're plagiarizing, there's no way to 'cheat' while making artwork. You simply start with a goal (or intent), and then create an artwork using your available tools. Certain techniques, however, are limiting in the long run and should be used cautiously.
Using grids on your reference photos
Artists are not copying machines. Illustration is about making intentional choices - emphasizing certain aspects while de-emphasizing others. As a professional I can tell you with complete certainty: copying with a grid is not a good way to learn drawing technique. This method breaks your subject into abstract sectors, eliminating an understanding of form and structure. If you were required to draw the same object from a different camera angle, you'd be totally out of luck. It's not to say reference material is unimportant - quite the opposite. But reference material is most useful when understood - not when mindlessly copied.
The one exception to this argument is for complete beginners. Drawing with a grid is a great way to draw what you see, and to avoid drawing stereotypes or icons. Like the drawing on the right, beginners often draw a house as they envision it, not like it exists in reality. Using a grid forces an artist to truly draw what they're looking at. Once you've internalized this lesson, I'd encourage you to drop the grid from your toolbox.
Visual measuring vs. grids
Your next question might be "what's the difference between using a grid and using my pencil to do visual measuring?" Though similar, visual measuring takes place in 3D space, and grids are used on photo reference. Drawing from direct observation requires an understanding of form and space - requiring the artist to translate what they're observing onto a 2D plane. Using your pencil to measure angles does not turn the task into mindless copying. Even with careful sighting and measuring, you're still required to understand the form and structure of your subject. In short, it's hard. It takes practice. Photo reference with a grid does not require the same analysis - you can simply copy one square at a time until your image matches the reference. Once again, grids are not 'cheating' - they just don't make you a stronger artist in the long run.
Using precise tools: rulers, 3D software, french curves, etc.
Beginners often worry that using a ruler is a sign of weakness. It's not. If your drawing requires precise, straight, lines - a ruler is your best friend. The big divide between this sort of tool and a grid on your photo reference is understanding. I might use a ruler to ink my line drawing, but the drawing itself was only possible because of my fundamental drawing skills. Understanding perspective, lighting, form, and anatomy allows me to put my idea on paper -- the ruler simply allows me to add a bit of polish. In this example my knowledge and understanding are the real tools, and the ruler enhances my execution. Grids are not like rulers.
Even though copying a photo with a grid could be described as 'precise', the objective is entirely different. Instead of empowering your creativity, a grid limits your potential. It allows you to copy extremely successfully - but that's the end of its usefulness. If asked to re-draw the same image from your imagination, you'd quickly realize how little you learned about your subject.
What tools should you use?
Any tool that allows you more control in your art is worth using. If you're unsure, ask yourself this question: "will it discourage me from learning about my subject?" If yes, the tool should be used sparingly. Your goal should be to learn with every image you create, focusing on long-term growth. Some tools can stunt your growth. Even if a grid can provide immediate precision, it doesn't give you any lasting insights.