To make a pattern for a custom size RV mattress, you’ll need a large piece of paper, or plastic, and a heavy marker like a Sharpie to trace the pattern. You should trace the exact shape of where the edges will be, indicating important things right on the pattern like the thickness of the mattress, and where any zippers might go if you’re going to have a cover on the RV mattress. Another important thing to determine is if the top and bottom of the mattress are the same, or if one has a slightly bigger size than the other (generally known as a bevel). If this is the case, you’ll need both a top and a bottom pattern, or must be able to communicate how much smaller one is than the other with your written instructions. As you go through the order process on our website, select the “Pattern Shape,” and you’ll enter the general dimensions of the mattress. At the end of the process we’ll tell you how to mail the pattern to us. Custom pattern shape mattresses usually take 2 weeks after we receive your pattern if they don’t include a sewn cover. If they do include a cover, it will likely take 4–6 weeks.