First, started with a square of white cardstock. Then, make a pattern for the grids by cutting a second square into 3 random pieces. A pattern is not necessary but if you are going to make several cards the same a pattern will help. Then, trace the pattern pieces with a Sharpie marker to get the black lines.
Next, mask off each section, one at a time and stamped the images with black ink. Once again, masked them each again, sponging them with 3 different colors of ink. It really doesn’t matter if you stamp first or sponge first. If you stamp first, then you have a little more control over where your lighter, highlighted areas are.
The second way to do this technique is to not draw in any lines. If you choose to use this technique you must do your sponging first. Then, mask off and sponge each section. The sections may overlap if you want. Continue until you fill the cardstock. Then come back and mask the sections again, this time stamping various coordinating images in each one. By doing it this way, it is sometimes best to choose only 2 colors of ink that blend well together to avoid the sections looking “muddied” where they overlap.