Speedball Art Products-Fountain Pen Ink Cartridges. Quality, free- flowing ink developed for use with Speedball Calligraphy Fountain Pens (sold serparetly) to provide a superior writing experience that allows artists to create beautiful results easily. This 2- 7/8x1-3/4x3/8 inch package contains ten black ink cartridges. Conforms to ASTM D 4236. Imported.