For its PERPANEP line (an anagram of "pen" and "paper"), Kokuyo has optimized the compatibility between different paper textures and pen types to offer 3 different pairings:
- Smooth (Sara Sara) [75 gsm] - Designed for use with water-based gel pens, like the Kokuyo x Zebra SARASA Clip PERPANEP - 0.5mm. Also works with oil-based ballpoint pens and pencils.
- Textured (Zara Zara) [90 gsm] - Designed for use with fountain pens, like the Kokuyo x Platinum Preppy PERPANEP - 0.3mm. Also works with plastic-tipped fineliners.
- Ultra-Smooth (Tsuru Tsuru) [96 gsm] - Designed for use with plastic-tipped fineliners, like the Kokuyo PERPANEP Finewriter - 0.35mm. Also works with felt-tipped pens and fountain pens.
This plastic-tipped Finewriter, which is exclusive to the Kokuyo PERPANEP line, is designed for use with the Kokuyo PERPANEP Notebook - Ultra-Smooth - A5, which is silky smooth with little resistance.
- Black water-based ink