I got the mats from an Amazon dealer a while back. They came in a large cardboard box which is great for storing and transporting them. 18 of the mats have waterways in addition to the roads. The mats are available in different colors, but I got black ones due to the discounted price. Only one side of the mats is smooth with the other side being ridged. I had a cheap can of cast off brown paint that I got from Home Depot. Colored paint is made by adding colors to a can of white base. At times the person mixing the color will make a mistake, creating the wrong color for the customer and have to make another can of the correct color. The mistakes are usually put aside in a group and sold at a discount,
I painted the entire surface of the smooth sides of the mats and let them dry. Next I painted the waterways. These were offset from the center of each edge by about 4 inches, lining up with the middle of one of the interlocking tabs. Six of the mats have branching waterways, six have curves that exit at different points, two go straight across from one side to the opposite. two shift from the left to right as they cross (one is at the bottom left), while the last two shift from right to left. The rest of the mats do not have waterways.
The roads were taped off with 3/4 inch (20mm) painters tape and are centered on the edge of the mats. The road pattern varies from mat to mat and tends to conform to the waterways. White glue was spread on the mats using a one inch paint brush avoiding the waterways. Mixed green ground foam from Woodland Scenics was sprinkled on the glue, and the excess shaken off to be collected for the next mat. The mats are another intermittent project that I work on as time permits. There are nine left to finish.