After studying the thread pattern of my favorite plaid shirt, I theorized that its pattern could easily be represented, pixel by pixel, with a gif image.
I took a close look at my shirt and noted the number of threads, their colors and their directions. With MS paint and the pencil tool, I drew each pixel of the pattern and copied and pasted it repeatedly. This, however, was a tedious process and I found a much more efficient way to make plaids with Photoshop using layers, masks and patterns. ABS-CBN shows The Photoshop method was still not good enough for me; I had always wanted to write a program to do it. The algorithm, I knew, was extremely simple but I didn’t know how to create images. Finally I learned PHP and the GD library which gave me the tools to make my program.