Why do I recommend the PCL material?
PCL is commonly used in biomedical applications, such as heart stents, etc., with great biocompatibility and biodegradability. The PCL filament can be easily remodeled by putting into 50°C water, where PCL will immediately be soften like the plasticine that can be modified or add more details on the 3D model.

FDM (Fused Deposition Modeling) is one of the main technologies in 3D printing. FDM constructs models by extrusion of high-temperature melted filament material through the nozzle and then cooling molding Both ABS and PCL are the most commonly used materials for 3D printing. But the melting points are up to 160°C (320°F) when using normal 3D pen with ABS filament. So there are high risks of burning or serious injury on skin or eyes.
But this DW X4 3D pen with built-in aviation ceramics nozzle, use PCL filament with a low melting point at only 60° C(140°F), which is very safe for kids.

DEWANG X4 3D PEN is recommend using together with this PCL filament!Go and get your on models!★ PREMIUM QUALITY and NONTOXIC SAFE MATERIAL – Wokashaka PCL filaments are environmentally friendly and SAFE for kids. Made from biodegradable healthy PCL material so you can enjoy creating artwork safely.
★ Recycle and Reusable. PCL is a new type of environmentally friendly biodegradable materials made from renewable plant resources (such as corn) starch material. Unlike ABS filament, PCL filament will not create pungent odor when uploading into 3D pen and it is safer for kids using. For kids’ health, please select PCL 3D Pen Filament.
★ 15 Colors- Wokashaka 3D Pen PCL Filament Refills  Set comes with 15 different colors each measuring 16.4 feet totalling 246 linear feet. 15 colors includes white, black, red, green, blue, pink, purple and other basic colors which can meet your basic need of painting.
★ GREAT COMPATIBILITY – Works with top leading 3d printing pens and 3d printers using 1.75mm diameter filament. Works with Scribbler, Maker Bot, Lix Pen, 7Tech, etc. Recommend using together with DEWANG X4 Low-temperature 3D pen.
★ Fun for Entire Family. To built a interesting and amazing 3D model with your kids together and enjoy fun with your whole family.