Putting a Drawing Grid on a Digital Photo

Putting a drawing grid on a digital photo may seem like a small matter. For many artists, however, it’s a major challenge.

I can draw a horse in almost any position, but I can’t draw a straight line.

Even with a straight edge.

Sound familiar?

For years, I’ve developed the line drawings for portraits using the grid method of drawing from reference photos. I’ve been drawing that way for so long that I started before the days of personal computers and photo processing software.

In other words, I had to draw every single line by hand.

I hated it! I never seemed able to get the measurements correct and usually ended up having to correct distortions in the resulting drawings.

Eventually, I discovered drawing reference grids on pieces of plastic using permanent markers. I could then lay the pre-drawn grids over reference photos. I still had to draw a grid for each drawing, but that was better than drawing one on the photo, too.

Then along came computers and digital photos and I no longer had to draw grids of any kind! Woo-hoo! Jubilation and a happy dance!

Here’s how I put grids on reference photos now.

TIP: If my references are actual printed photographs, I scan them into the computer first.

Here’s my subject for this tutorial. I always look for good lighting from a clear light source, accurate color, and a minimum of distracting elements overlapping your subject.

How to Put a Drawing Grid on a Digital Photo

Step 1: Save your reference photo with a new name.

Open your reference photo, then select the “SAVE AS” option and save your reference with a new name. I usually use the working title for the drawing or painting.  You want to do this before you make any changes, even to color. That way, if you make a mistake you can’t correct, you can go back to the original photo and start over.

TIP: Save your photo periodically and rename it by adding a number (1, 2, 3, etc.) or letter (a, b, c, etc.) to the end of the name. These additional copies act as backups. You don’t need to save them forever, but they should be kept until you’ve finished all changes to your reference photo.

Step 2: Crop and resize the reference photo if necessary.

Do any cropping and resizing necessary and save it again. I generally name every document used for a painting with the title of the painting or the name of the horse and the date. This image was saved as grid-drawing-demo-01.jpg. Make sure the names you choose make sense to you and can be easily remembered.

Step 3: Adjust your rulers

Before you begin, make sure rulers are showing. Photoshop’s default setting is to have the vertical and horizontal rulers showing.

You can change the measurements if you wish, if the default setting of inches doesn’t work with the size of your photo. Most photo editing software allows you to hide or show rulers, and also choose inches, millimeters, picas, and other measurements.

Step 4: Add a new layer to the photo.

Before you begin drawing the grid, add a new layer. In most versions of PhotoShop, click on the drop-down LAYER menu, click on ‘NEW’ and select ‘LAYER’.

NOTE: I’m using PhotoShop 7.0 on a Macintosh G4. Your drop-down menus may look different.

Step 5: Begin drawing the grid.

Now you can draw the grid on the new layer. Select the LINE DRAWING tool from the toolbox on the left (see the gray box in the image below).

Choose a color that shows up well against whatever image you’re working with. Black works with most. White works best with most darker images, but I’ve also used red or blue, depending on the color, value, and color temperature of the image.

Choose the space between the lines that best suits your project. I draw lines at one inch intervals. Beginning at the top left corner, I draw the first line at 1″ and continue across the image to the right.

Return to the upper left hand corner and draw lines along the left side.

To get straight lines and square boxes, hold down the shift key as you place the cursor and while you draw the lines.

Step 6: Number the grid

The last step in the process is numbering the grid. Select the TEXT tool from the toolbox (see the gray box on the left in the image below). Place the cursor in the upper left hand corner. Beginning with 1, type a number in each box across the top of the image. Repeat this for the bottom row of squares and for the squares along the left and right sides of the image, if you wish.

If the image is very large, you may want to consider adding a row of numbers through the middle of the image and a column down the center.

This is the finished grid.

Step 7: Make a printable drawing grid.

The reason I draw the grid on a fresh layer comes into play at this point.

With the image on one layer and the grid on another, I can remove the image and have the grid alone. The grid can then be printed and used for the first draft of the drawing. Make sure to save the grid by itself.

You can also print the image with the grid in place (see the image for the previous step) and have a reference image and drawing grid that are the same configuration and are numbered the same.

Step 8: Prepare the grid and reference to be saved as a jpg file.

The final step is optional and that’s preparing the image to be saved as a jpg.

In PhotoShop, images with multiple layers are automatically saved as .psd files. PSD files are not suitable for most internet uses or emails. In order to save them as jpg or png files or any other online compatible files, you first need to flatten the image (combine the layers into one layer).

To do that, select the LAYER drop down menu and go to the bottom. Select FLATTEN IMAGE to combine all the layers into a single layer. You can now save the gridded image as a jpg file.

Recommendations

I highly recommend saving the image at least twice during the process. Once after the grid is in place and numbered but before you flatten the image (see Step 6) and again as the grid without the image (Step 5).

I also save the image afterward. With this ‘save’ I change the image to a JPG format. JPG files are generally smaller and more versatile than PSD files.

But don’t throw away those PSD files! You never know when you may need to go back to them to print another copy or resize the image or for some other unforeseen reason.

Conclusion

That’s how I put a drawing grid on a digital photo. It looks time-consuming and complicated, but even the most complex digital grid is much easier to make than hand drawing it.

As I mentioned previously, if you use something other than Photoshop, the commands and function names may be different. It is well worth your time to learn how to put a grid on your digital photos if you use the grid method.