[Revised Jan, 2021] It is sometimes difficult to paint large paintings plein air. After all, when we set up our easels in the out of doors, factors like uneven ground, heaviness of large canvases and wind make the large painting effort problematic. Especially wind, which can come up at any time, can be a problem. After all, our canvases are not unlike the canvas sails on a sailboat – they catch the wind and want to move!

So the problem arises about how to make those smaller plein paintings larger within the controlled environment of a studio. You can just eyeball the small painting as you begin the larger one, but a better approach may be to grid both the small painting and larger blank canvas. This grid will ease your positioning of the basic shapes.

To do this, we begin by covering the small painting with plastic, or placing it in a “sleeve”, as I have done here. (I’m working to enlarge one of my plein air paintings – Sea Spring.) Draw your grid onto the plastic overlay. Divide the  length and width into 3 equal sections, and draw horizontal and vertical lines to form the grid of 9 smaller rectangles. I also put 2 diagonal lines from corner to corner of the canvas.

(Also, if you are a collector, and want a smaller or larger version of one of my paintings, I would use this method to create the new resized painting for you. Contact me for more details and pricing.)

Next, you’ll want to choose a larger canvas that is similar in proportion to the small painting. Ideally, keep the same aspect ratio (height/width.) For example, a 9×12 painting is 3:4 (the “aspect ratio”), so an equivalent proportion in a larger size is 18×24 (multiply each dimension of the aspect ratio by 6.) Now put the same grid on the larger canvas. Again, put a diagonal from each corner of the canvases.

Your next step is to sketch the basic shapes onto the large canvas, letting the grid guide your placement of objects. You’ll begin to get a feeling for the larger image as you do this, and the sketch is your guide for adding color and detail.

Now you can begin filling in the painting. You may be surprised at how satisfying it can be to remake a painting you are proud of into a larger presentation.

Here’s my effort in progress. You can see the grid is disappearing as the painting covers it. I still have a ways to go, but this should give you the idea.

The final image, Shades of Blue, is on my website for you to see the final image. The enlarged painting has been sold to a collector.

This technique can also be used if your intention is to make a larger painting from just a section of the original painting. This may be the case if you are not entirely satisfied with the composition of the original, or if you just feel a portion of that original will scale better. Again place the original in a sleeve, and then simply mask with tape the portion not to be used in the new painting. Now draw your grid on the portion you are keeping. Be sure to select a canvas matching the aspect ratio of that section you want to enlarge.

Happy Painting!

PS. If you like this, or have a comment or question or other idea for a tip for artists, let me know below using my contact page.