TECH DEMO - How to Grid a Photo

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Description - Tutorial on how to use Photoshop or PaintShopPro to create a grid over a photo reference that is proportional to the intended painting surface.

If you are using a photo reference from a digital camera, and then transferring the initial drawing to a canvas or panel, this is the most direct method I’ve found for laying a temporary grid over the reference in photo editing software - PaintShop Pro or Photoshop. You could also print out the photo and draw a grid, but since digital photos have greater resolution, by using this method you can look at the image on your computer screen and zoom as needed while keeping the grid in precisely the same place. Also - no wasted paper or toner.

Notes for Photoshop appear in the descriptions as well, but all photos relate to PaintShop Pro on a PC.

First, we want to crop the photo reference to a size that is proportional to the canvas or panel. In this case, in PaintShopPro, I have selected the Crop Tool. Using the Tool Options toolbar, I’ve entered an initial size for the crop area of 300 x 400 pixels. Since my canvas is 9 x 12 inches, which is a proportion of 3:4, I want to start with something that is also 3:4, and 300 x 400 pixels is natural way to start.

Next, I want to make the crop area larger, but stay in that 3:4 ratio. By holding the Shift key down, I can drag the corner of the crop area out to an approximate size of what I want, and it will keep the same aspect ratio (proportions.) I can move the whole box around to where I want it, and resize as many times as I need as long as I hold the Shift key down.

When I like what I’ve got, I click the green check mark button (or double click inside the crop area) to activate the crop.

It’s a little different in Photoshop: Select crop tool, enter print size and resolution on the options bar, then crop. It will keep it proportional no matter how large your crop.

If I were going to print this out, now I would click Image > Resize to adjust the image to something that would come out of the printer, and possibly lose some of the data in the resizing. But since I’m not printing, I only need to know how big the image is so that I can determine how big the boxes are. In this case, the Original Size portion of the Resize dialog box says that the height is 22 inches. After remembering that number, I click Cancel to close the box.

By clicking View > Change Gride Guide and Snap Properties (File> Preferences> Guides & Grids in Photoshop) I can bring up the dialog box to set the grid size. How big do I want the grid boxes? I think a grid of 3 boxes wide x 4 boxes high should be plenty of information. Since I know the height is currently 22 inches, 22/4=5.5 inches. If I had wanted 6 x 8 boxes, I would have divided 22 by 8. And if I had wanted a 1 inch grid on my 9 x 12 canvas, I would have divided 22 by 12.

But I’m fine with the 3 x 4 boxes. So I set the Current Image Setting portion to 5.5 and click OK.

To show the grid, click View> Grid (View> Show Grid in Photoshop). So that’s it! Now I have a reference that’s proportional to my canvas, cropped to an attractive composition, and it has a grid already in place. By using the wheel on my mouse, I can zoom in and out easily, and always see where those grid lines are. After lightly pencilling in a corresponding 3:4 grid on my canvas, I’m ready to go. This process takes about 2 minutes. A real time saver!