Sketch a Digital Photo Quickly and Accurately using a Grid
If you would like to draw from a digital photo but are concerned about it looking natural and in proportion, then read on and discover how using a grid can help you draw quickly and accurately.
A popular technique for recreating, reducing or enlarging a drawing based on a photo, the grid method described below involves adding a brightly-colored grid over a digital image using Microsoft Paint, reproducing the grid with the same number of squares onto paper, stretched canvas, etc., and then using the grid as a guide to transfer the complete image from computer to the work surface.
For those who are making a pencil sketch, simply erase the lines when the sketch is complete. For those making a painting based on a favorite photo, such as in the hub How to Turn a Photo into an Acrylic Pop Art Painting, the pencil marks will be covered during the painting process.
What you need to prepare
A digital photo
Paper, canvas, etc.
Why draw using a grid?
- Recreate, reduce or enlarge an image that you want to paint or draw more accurately
- Helps to improve drawing and observational skills compared to tracing
- Removes stress of knowing where to start
- Perfect for times when tracing is not possible
- Makes drawing less complicated
- Helps the artist focus on smaller shapes of subjects
- Easy to judge relative distances and reproduce them
- Helps overall drawing skills by training visual memory
Why use Microsoft Paint?
While there are plenty of alternative graphics software programs and free online photo editors that provide the same basic functions, MS Paint offers the following advantages:
- Extremely easy to use; perfect for children and inexperienced computer users (versus Photoshop)
- Comes pre-installed with every computer using a Windows Operating System (versus Photoshop)
- Doesn’t require an Internet connection to run (versus free online photo editors)
Paintbrush for the Mac is a painting and illustrating program very similar to MS Paint.
How to open a photo in Paint
1. Go to the file location and right-click on the photo.
2. Click Open with and then select Paint.
1. Click on Start, All Programs, Accessories, and then Paint.
2. Click on the File menu and click Open.
3. Go to the image location and double click on the photo.
Saving the new image
It’s a good idea to save the image immediately upon opening in Paint to prevent accidently saving over your original photo. If you make changes to the photo before changing the file name and select Save from the file menu or press Ctrl+S, your original photo will be overwritten with this new modified image.
1. After opening the photo in Paint, go to the File menu at the top left and select Save As...
2. Select JPEG picture (JPEG is a commonly used format for saving photographs at a smaller file size).
3. Choose a location for your new photo with grid. For simplicity, you can save the photo to your desktop.
4. The original name of your photo will appear in the File name box. Either delete this and type a unique file name or simply add the word ‘grid’ to the end of the original name.
5. Click Save at the bottom of the window.
Crop an image in Paint
This is an optional step for those who wish to draw only a specific area of a photo. It involves deleting all parts you don’t want to draw in the final image from the digital photo. This lets you make a more efficient grid, which helps sketch the final image.
1. Go up to View and select Zoom Out so you see the whole photo on the screen.
2. Click on the Selection tool (the one that looks like a rectangle with dotted edges).
3. Click and drag to select the area of the photo you want to draw. You can do this as many times as necessary to get the perfect area. Keep in mind that the shape and scale of the rectangular area you select should be similar to your paper or canvas.
4. Go up to Image and select Crop. This will remove all parts of the photo outside the area you selected, leaving just the part you want to draw.
5. Go back to View and select Zoom In.
Resize an image in Paint
If you can’t view the whole photo on the screen after opening (and cropping, if necessary) in Paint, which is often the case for photos taken with a high-resolution camera, you will need to resize the image first. This will make it easier to add a grid as well as help with sketching later.
1. Go to the Image menu and select Stretch/Skew or simply press Ctrl+W to open the Resize and Skew window.
2. Delete the number 100 and type a lower percentage to reduce the width in the Horizontal box and the same percentage to reduce the height in the Vertical box. Just to reiterate, the number in both boxes should match.
3. Click OK.
4. If the entire image is still not visible, either click on the Undo arrow at the top left or press Ctrl+Z to undo the action and repeat the steps above using a lower percentage.
When you have adjusted the size so that the whole photo fits on the screen, go to the file menu and press Save or press Ctrl+S.
Drawing a grid in Paint
Opening your photo in Paint, saving it with a new file name, and resizing the image should only take a couple of minutes to complete. Adding grid lines to the photo will take a bit more time but the end result is definitely worth the extra effort.
This step requires making an initial calculation to get the ideal grid size on the work surface. Guides to using other methods, such as making a grid of 1” boxes, are available online but they can be difficult to transfer precisely onto a canvas unless you are drawing to the same scale. The method described below is slightly trickier but it takes the canvas dimensions into account first to help with enlarging the image. I will describe the steps first and then use 2 examples to illustrate in more detail.
Use the table below to work out the ideal paper or canvas size based on the dimensions of the image in Paint:
1. Put your cursor at the very bottom right-hand corner of the image in Paint.
2. Look at the bottom of the window to see the total dimensions of the image.
3. Look for the nearest match in the table below to find out the size of canvas you need.
Table: Canvas vs. Image vs. Box size
Common Canvas Sizes
Image Size in Paint
Box Size (No. of boxes)
12 × 12"
300 x 300 px
2” (6 x 6)
14 × 14"
360 x 360 px
2” (7 x 7)
16 × 16"
410 x 410 px
2” (8 x 8)
18 × 18"
460 x 460 px
2” (9 x 9)
20 × 20"
510 x 510 px
2” (10 x 10)
24 × 24"
610 x 610 px
3” (8 x 8)
30 × 30"
760 x 760 px
3” (10 x 10)
36 × 36"
910 x 910 px
4” (9 x 9)
40 × 40"
1020 x 1020 px
4” (10 x 10)
50 × 50"
1270 x 1270 px
5” (10 x 10)
18 × 12"
460 x 300 px
2” (9 x 6)
24 x 12"
610 x 300 px
3” (8 x 4)
20 x 16"
510 x 410 px
2” (10 x 8)
24 × 16"
610 x 410 px
4” (6 x 4)
30 x 20"
760 x 300 px
2.5” (12 x 8)
36 x 24"
760 x 1020 px
4” (9 x 6)
60 × 40"
1520 x 1020 px
4” (15 x 10)
24 × 12"
610 x 300 px
3” (8 x 4)
30 × 15"
760 x 380 px
3” (10 x 5)
40 × 20"
1020 x 510 px
4” (10 x 5)
60 × 30"
1520 x 760 px
5” (12 x 6)
To work out the best grid size to match the paper or canvas size:
The following 5 steps may not make sense the first time you read them. I encourage you to read the examples that follow and then return to these steps with a clearer understanding.
1. Calculate the smallest number divisible by both the length and height of your canvas to give you the box size in inches. See table above for common canvas sizes and corresponding box size.
2. Divide the length of the canvas by the box size to give the number of boxes you need to draw across the image.
3. Divide the length of the digital image by the number of boxes to get the spacing between vertical lines of the grid.
4. Draw the vertical lines on the image in Paint, with each line separated by the number of pixels calculated in 3 above.
5. Repeat steps 2 to 4 with the height of the canvas and complete the grid with horizontal lines.
Making a grid example 1: Portrait
I want to paint an image in portrait orientation that is 444 x 518px in Paint. From the table I see that these dimensions would be best suited to a 20 x 16” stretched canvas using 2” square boxes, and with 8 boxes across and 10 boxes down. Therefore, to make the grid in Paint I need to divide 444 by 8 and 518 by 10.
- 444 / 8 = 55.5 I can’t use this because there is a decimal place. So to round down to 55, I need to delete 4px from the image in Paint to give me a width of 440. 440 / 8 = 55, perfect.
- 518 / 10 = 51.8 I can’t use this either because of the decimal point plus I want it to be close to the 55 from above to give me an almost square grid. I simply expand the image height in Paint by 2px to give me 520px and then 520 / 10 = 52, perfect.
Now I know I need to draw a grid of 55 x 52px on the image in Paint.
- I choose a bright color that will stand out from the image and starting from the left edge, I count in 55px and draw a vertical line from top to bottom.
- I move in another 55px to 110px and draw another vertical line.
- I continue in this way until I have drawn the seventh and last line at 385px.
- Similarly, starting from the top edge, I go down 52px and draw a horizontal line from left to right.
- I then move down another 52px to 104px and draw another horizontal line.
- I continue in this way until I have drawn the ninth and last line at 468px.
The image grid is now complete. It’s time to move on and draw the 2 x 2” pencil grid on the canvas.
Making a grid example 2: Landscape
I want to paint an image in landscape orientation that is 741 x 381px in Paint. From the table I see that these dimensions would be best suited to a 30 x 15” stretched canvas using 3” square boxes, and with 10 boxes across and 5 boxes down. Therefore, to make the grid in Paint I need to divide 741 by 10 and 381 by 5.
- 741 / 10 = 74.1 I can’t use this because there is a decimal place. So to round down to 74, I need to delete 1px from the image in Paint to give me a width of 740. 740 / 10 = 74, perfect.
- 381 / 5 = 76.2 I can’t use this either because of the decimal point plus I want it to be close to the 74 from above to give me an almost square grid. I simply reduce the image height in Paint by deleting 1px from the bottom to give me 380px and then 380 / 5 = 76, perfect.
Now I know I need to draw a grid of 74 x 76px on the image in Paint.
- I choose a bright color that will stand out from the image and starting from the left edge, I count in 74px and draw a vertical line from top to bottom.
- I move in another 74px to 148px and draw another vertical line.
- I continue in this way until I have drawn the ninth and last line at 666px.
- Similarly, starting from the top edge, I go down 76px and draw a horizontal line from left to right.
- I then move down another 76px to 152px and draw another horizontal line.
- I continue in this way until I have drawn the fourth and last line at 304px.
The image grid is now complete. It’s time to move on and draw the 3 x 3” pencil grid on the canvas.
Drawing the grid on paper or canvas
Try to use a very light pencil, such as a 3H, to draw the grid on the paper or canvas. From the calculation above, you know what each square is in cubic inches. To draw this grid using the first example above, put your ruler at the top of the canvas, and make a small pencil mark every 2 inches. Continue all the way round the edges of the canvas. Then use the ruler to make a straight line connecting the marks on each side of the canvas to the corresponding mark on the opposite side.
Sketch photo on canvas
With the full grid now complete, use the pencil to lightly sketch each box from the image to the canvas. It doesn’t matter where you start or if you sketch boxes in a certain order. When sketching, the grid lines will guide you to measure and draw lines accurately.
For really difficult parts, such as drawing eyes, you can split a single box into another 4 boxes on the digital image first and then on the canvas. This is a good training technique to learn how to draw realistic eyes.
You can use an eraser to get rid of grid lines when you want to complete the sketch or simply start painting and the paint will cover both the grid and pencil sketch.
Improve drawing skills with grid lines
Making sure every feature is in proportion makes portrait drawing one of the hardest elements a learner has to deal with. This is why grid lines are an ideal way to train yourself to find individual shapes within a subject as well as measuring the distance between them. When the grid and sketch are complete, you should already have something that closely resembles the digital image. With practice, the calculation used to make the grid on the digital image will become second nature and sketching the image will be finished much faster. In fact, you may find that you don’t need to draw a full grid; only using a small one for difficult parts, such as the eyes.