Love them! A must buy. You can use any pen you would like our that you have on hand. Just match up the pen holder with the own you are using, place pen holder in machine just like you would with the blades, and change your settinger to sketch pen. As much as I like the silhouette brand pens I would prefer to use my own or go buy any pen I want so I wouldn't have to wait on then to come in and I would have said greater assortment to chose from.