They work on nearly all surfaces and are suitable for both indoor and outdoor use

These pens have a water-based ink that won't bleed through your paper (applies to paper weights of at least 80 grammes)

The pen comes filled with blue archive proof ink and each cartridge writes 8000 meters

so your sketches stay clean and safe over time

clairefontaine tracing paper pad a4 Ink and paint refills They work on nearly allThe Clairefontaine Tracing Paper Pad in A4 offers a high quality, highly transparent surface that is perfect for both technical and creative work. This environmentally friendly alternative to plastic is fully biodegradable and recyclable, while being acid free and pH neutral for long lasting durability. The paper is remarkably strong, allowing erasing or scraping without tearing, making it ideal for graphite, colored pencil, felt tip, marker,