This tool is made to accompany the book “Structure of a Masterpiece” www.moydanart.com
The patterns can be made with either a light gray, 38% black, or a dark gray, 62% black. 
The patterns are automatically cleared whenever you switch between grays or go to this information page. Take screen shots of patterns you wish to save.
This pattern tool is designed to aid in making a specific style of pattern. Each finished pattern should have three values, white, gray and black. The relative proportions of the values is also important, 19 squares of one value, 11 squares of another value and 6 squares of the remaining value. It’s your choice which value goes in which portion of the ratios (19:11:6). Also you can position them on any square on the grid you chose. Drag the squares to the grid to position them. 
To the left of the grid are textures that can be used to visually balance out the pattern after the values have been applied. Use the textures sparingly or you will alter the proportions of the values to too great a degree.