We know the measuring part got tricky, but we've broken it down in the steps below:
While you can just eyeball the spots, we like the look of straight lines. Start by using the two handles as starting points for the two row of spots and create two rows of dots, making sure the space between each is the same.
The middle row of dots should be spaced between the ones on either side of it. To figure out where each dot should be placed, just find the intersection between the two diagonal bisections of four dots. In other words, find the middle of the square of dots!
Using a flat edge, connect three dots spanning the three rows to create a diagonal line and measure out the dots for the further rows. Make sure all the spacing is the same! For wider bags, you may have to repeat this step!