What are some alternatives?
When comparing Quill by Story Studio and SprayPrinter, you can also consider the following products
A-Painter - Paint in VR in your Browser
Tilt Brush by Google - Paint in spaces around you with Virtual Reality
Oculus Medium - Sculpt, model and paint in virtual reality on a 3D canvas.
VR Sketch - A tool for designers to draw inside virtual reality
MasterpieceVR - Powerful VR sculpting & painting tool
AI Painter - Turn your photos into paintings