Crayon Protector Design Enhancement

I already sketched a simple sleeve meant to stop a single crayon from snapping in half, but the idea still feels rough. I need a product-minded designer who can turn this concept into a child-friendly, manufacturable solution aimed at kids aged 4–7.

Here is what I’m trying to achieve:
• Primary goal: prevent breakage—one crayon at a time.
• Ergonomics must suit small hands without adding bulk that makes colouring awkward.
• Materials have to be safe, non-toxic and sturdy enough to survive classroom drops.
• Aesthetics should be playful so it actually gets used rather than tossed aside.

Deliverables I’m expecting:
1. Two or three refined design options presented as 3D CAD files (STEP or STL) plus simple renders so the form factor is easy to judge.
2. Basic engineering notes on wall thickness, material choice and any snap-fit or twist mechanism you suggest.
3. A short paragraph on production considerations—whether injection moulding, simple extrusion or another low-cost route suits the proposed design.

If you have experience with child-oriented accessories, toy safety standards or quick prototyping, that will help us move rapidly from idea to testable sample. Let’s make this little sleeve strong enough to keep crayons intact yet fun enough that kids actually want to use it.