One of the minor problems i encountered with leaning to work with cold wax is that it comes in jars. Which is ok in the studio but I found myself contaminating the clean wax with color when digging it out of the jar with a knife. I also didn't like the big blob of wax on my palette. Again, i was contaminating it with color as i try to use it to mix with paint. When painting on location, the jar is really inconvenient. Bulky to carry, easy to contaminate the entire container, you need two hands to open and close it, it dries out if left open and I'm sure there are more. So here is my solution. Take an empty toothpaste tube and cut the bottom off, rinse it out well, dry and use a knife to load it from the bottom with cold wax. Tap in on the bench to force the wax to the "business" end of the tube. Roll up the end and clamp it shut. Now it's easy to lay out a line of wax on the palette in small, or just the right amounts, as needed. Clean and fresh wax every time.