Perie Inkless Pen Made of Bamboo. This Pen Does Not Require Ink Cartridges or Refill & It is a Durable Writing Instrument Simply Because the Pen Tip is Designed to Leave Visible Traces as It Makes Contact with the Writing Surface. Choosing an Inkless Pen Made of Bamboo Promotes Making More Sustainable Choices, & Encourages the Use of Renewable Materials. Nib Size: 1.00 Mm. Minimum Quantities Apply.