Want to use an alternate ink cartridge for your Pen Type-A or Pen Type-B? You'll need a small spacer to fill up the extra space on some cartridges. You can buy these little spacers here, or cut a piece of tubing or a wooden dowel to the appropriate length. Check below for the appropriate length for your ink cartridge. Our favorite alternative is the Pilot Hi-Tec-C Coleto. They're reliable and have a huge selection of colors. Pilot Frixion is also super interesting because it's an erasable ink that works like magic. Check out the video below ↓ Ink Cartridge Spacer Length (6mm diameter) Pilot Hi-Tec-C (BLS-HC25, BLS-HC3, BLS-HC4, BLS-HC5) BLS-HC3 ships with our pens.Here's a comprehensive guide to Hi-Tec-C. no spacer needed Pilot G-Tec-C (Identical to Hi-Tec-C, sold outside Japan with fewer color options) no spacer needed Pilot G2 (Widely available gel ink) 5mm Pilot Juice (color gel ink) 4mm Pilot Frixion (Erasable Gel Ink) 4mm Pilot Hi-Tec-C Coleto (huge selection) 21.5mm Zebra EQ (Ultra smooth and vibrant emulsion ink) 2mm Zebra JF (Highly durable fine tip) 3mm Uni Signo UMR-82, UMR-83, UMR-85, and UMR-87 (Super smooth edgeless tip) 3mm Uni Zento 3mm Muji Gel-Ink 3mm Uni Signo UMR-109 (Gel ink available in white, black, gold and silver) 16mm Uni Jetstream SXR-80 (Tip sizes up to 1.0mm) 27mm Schmidt 6040 FineLiner Fiber Tip (Spring loaded felt tip) 6mm Pentel Energel 3mm
