Made to stand out on the deepest hues of paper, cardstock, and labels, these opaque gel pens add a pop of personality to your cards, paper crafts, and decor. Embellish even your darkest materials - it's easy add a playful note or a fun drawing with your Cricut Joy machine. Compatible materials include Cardstock, Paper, Cards, Smart Paper Sticker Cardstock, Smart Label Writable Paper. Not compatible with regular vinyl.