Write an article based on this "Obtain a large plastic storage container. Measure and mark the mold. Spray the container with non-stick cooking spray."
Find a container that is 12 (h) x 12 (w) x 20 (l) inches in size. Avoid containers with patterns on the sides or bottom, as it will make removing the gel more difficult. Measure the inside wall 6 inches (15.2cm) from the bottom of the container and mark it with a permanent marker. This will be the line that you fill the water to. Coat the entire inside with spray to help release the gel when it is finished. Wipe any excess spray out to avoid cloudiness in the finished gel.