Here is an easy to follow picture tutorial on how to paint a harlequin pattern on a bedroom wall.
The Before and After:
First, paint the wall with your basecoat color. I used a lighter paint color as my base color (I used Behr Premium with Primer in the Paint – Expedition Khaki) and I chose a slightly darker shade for the lines (I used Behr Premium with Primer in the Paint – Beachwalk). Here, I measured left to right and top to bottom and found the center of the wall. Mark this point with a pencil.
Use a pencil so you can erase your grid lines with a wall eraser or Mr. Clean eraser later. I used a long level and drew a line strait across, horizontally. I wanted the diamonds to be 9 in wide, so i marked 4.5 inches to the left and then 4.5 inches to the right of my center mark (I marked on the line I drew with the level, so it would be exact). Then, I did the same thing, only top to bottom, except, since I wanted the diamond shape to be 18 inches, I measured 9 inches above the center mark and 9 inches below it (again, I marked on the lines I drew with the level).
Center mark. Then, left at 4.5 inches, right at 4.5 inches (to make the diamond 9 inches wide), and 9 inches top and 9 inches bottom of center mark (to make the diamond 18 inches tall).
Step 3: Start creating your grid. You are going to erase all of your pencil lines later, so don’t draw your lines too dark if you can help it.
Here is a better idea of what your grid will look like all across the wall.
Step 4: Start connecting the points for the the diamond.
Step 5: Just keep following your grid lines to create the same pattern across the entire wall. After you have drawn out all of your lines with a pencil, go over just the diamond pattern with your secondary paint color, using a small paint brush. Again, only paint the lines that create your pattern. The grid is just to keep everything straight and even.
Step 6: Erase the pencil lines. I used a Mr. Clean Eraser. Then, I went over the lines I had pained one more time, so they completely covered the pencil marks. I also used my base paint color to go back and fill in any areas that I thought looked crooked or the lines appeared too thick. Enjoy!