Gina K. Designs -. Designs Ink Cubes are acid-free and PH-Neutral. They are convenient for travel and easy to store. They are an economic way to collect lots of colors and they coordinate with our exclusive card stock. This set includes: Red Velvet, Prickly Pear, Red Hot, Powder Blue, Cherry Red, Blue Denim, Christmas Pine, Edible Eggplant.