The Importance of Canvas Size Ratios in a Painting

What is a Ratio?

Let's understand what a ratio is before we get into the artsy stuff. A ratio is a relationship between two numbers that indicates how many times one value fits within another. In art, the ratio of a canvas refers to the relationship between its width and height.

For instance, a 9×12 canvas has a ratio of 3:4. For every 3 units of width, there are 4 units of height. Easy, right? Now, let's see how this ratio plays into your art.

Why is the Correct Ratio So Important?

Keeps the Composition Intact

Composition is how you place different elements in your painting. Imagine painting a tree that perfectly fits the 9×12 canvas, but when you scale it to a 16×20, the tree either looks too stretched, squeezed, or cropped. This throws off the balance and makes the whole painting look off.

Preserves the Details

When you change the ratio, details can get lost or exaggerated. A proportionate bird on the 9×12 canvas could look like a flying dinosaur on a 16×20!

Maintains the Focal Point

The focal point is where you want people to look first when they see your painting. Changing the canvas ratio could shift this focus, making your audience look elsewhere first. That's like telling a joke but messing up the punchline!

But I Don't Have the Right Size!

So you might be wondering, “What if I only have a 16×20 canvas?” Don't worry! The trick is to keep the same ratio. In that case, you should look for another tutorial designed for a canvas with a ratio that matches your 16×20, which is 4:5. Alternatively, you can adjust the painting's composition to fit your available canvas while keeping the elements in proportion.

The Size Chart Solution

For those wondering which sizes will work with the tutorial you have in mind, check out the size chart. It removes the guesswork and ensures your masterpiece turns out just how you envisioned.

Canvas Sizes and their Equivalent!

Ratio – Canvas Sizes

• 3 to 4 = 3×4 – 6×8 – 9×12 – 12×16 – 18×24 – 30×40 – 36×48 
• 5 to 7 = 5×7 – 10×14 – 20×28
• 4 to 5 = 8×10 – 16×20 – 24×30
• 5 to 6 = 10×12 – 20×24
• 11 to 14 = 11×14 – 22×28
• 1 to 1 = 6×6 – 12×12 – 18×18 – 20×20 – 24×24
• 1 to 2 = 6×12 – 8×16 – 12×24
• 7 to 9 = 7×9 – 14×18 – 21×27 – 28×36
• 2 to 3 = 2×3 – 6×9 – 12×18 – 16×24 – 20×30 – 24×36

The bold numbers above are the ratios, and the italic numbers are the canvas sizes we normally use.

Conclusion

When it comes to acrylic painting, size and ratio matter. Using a canvas with a different ratio from the tutorial you're following is like trying to fit a square peg into a round hole; something will go wrong. Stick to the recommended canvas size or adjust the ratio to ensure your artwork turns out as beautiful as possible.

So the next time you see a tutorial you love, double-check your canvas size. Trust me, your artwork will thank you!

Best Wishes,
Ginger Cook
Professional Acrylic Artist and Educator of Acrylic Painting