Often used to encode top-secret information, invisible ink has a long and interesting history dating back to the 4th century BC. There are all kinds of ways to make and read invisible ink (like heat and lemon juice), but our Invisible Ink Thinking Putty® uses ultraviolet light to mimic blue ink on a sheet of green paper. Write with the Glow Charger® and watch with wonder as your words evaporate into thin air.

Thinking Putty® helps build hand and finger strength through a fabulous tactile play experience with unique, unexpected properties and provides relaxing, yet stimulating interaction for anyone with sensory integration issues.

Crazy Aaron's putty is non-toxic, won't dry out, and won't leave a sticky or slippery residue on your fingers, so it's great for stretching, molding, bouncing, tearing, popping, and playing by kids and adults alike.

• Collection: Glow
• Includes tin with  1/5 lb. (3.2 oz) of putty and a Glow Charger®
• Color: Green that glows dark green
• Features: Glow-in-the-dark, Stretchable, Sculptable, Soft Texture
• Materials: Non-toxic silicone
• Ages: 3+
• ⚠️ Warning: Choking Hazard. Contains Small Parts
• ⚠️  Warning: UV emitted from this product. Avoid direct eye or skin contact with light. DO NOT aim light at people or pets.
• Never dries out
• Proudly made in the USA
• Manufactured with the help of exceptional individuals challenged with disabilities