This is a print‑in‑place folding case for 12 or 18 markers or pencils with a diameter of about 8.3 mm and a length of up to 150 mm, ideal for Centropen Colour World markers and other brands with similar dimensions.
Conventional blisters and cardboard boxes are hard to close, do not show which colours are missing, and often lead to lost caps and incomplete sets scattered in a “junk” box.
This case has two hinged halves that snap closed with an integrated clip, keeps each marker securely in place using individual clips, and makes it instantly visible whether the whole set is complete, which helps children keep their stationery organised.
It prints as a single assembled part (print in place), is easy to transport, and is designed so markers do not fall out even when carried in a backpack.

For best durability, PETG is strongly recommended; use a well‑tuned printer to ensure excellent layer adhesion, otherwise the hinge and clip may break under repeated use.
Suggested settings: infill 10–50%, no brim, no supports, standard 0.2 mm layers are fine for PETG print‑in‑place mechanisms.

If you are unsure about the fit, please first print the included 2‑slot test piece; you can then use it as a small 2‑marker holder.​
If the test shows your markers are looser or tighter, just tell me the exact diameter and length of your markers or pencils and I will prepare additional versions.
Please also send me the dimensions of your favourite marker or pencil sets so I can gradually add more case sizes tailored to as many different brands as possible.

Feel free to download and try this model, and if you like it, please share it, leave a rating, and give it a boost so more parents and makers can keep their kids’ markers tidy.​
If you need a different capacity, layout, or a completely different organiser for your stationery, just write a comment with your idea and required dimensions.​