I use liquid, but I mix my own blocks in dixie cups. I have basic colors and mix orange - for example - I write the number of drops of red and yellow on the side of the dixie cup then fill it about 3/8" full of wax. Mix it and let it harden. Then if I need just a shave of a color, I can get it. If I need a deep color, I know how many drops of each will make my desired shade. I have bottles of liquid that I have had for years and they still work perfectly well.