Two wheel or three wheel kaleidoscope: a neutral decision guide by viewer, use, image, handling, light and engraving.

How coloured glass is worked for kaleidoscope wheels: cut sheet glass, kiln-fused glass, lampwork, frit and stringers, and what each does to the image.

How kaleidoscope wheels work: object wheel vs closed cell, two or three wheels, colour mixing by overlap, counter-rotation, light and how to turn them.

What goes in a kaleidoscope object cell: Brewster's rules for object shape, transparency, colour, fill level and motion, and the cell formats in use today.

How an oil-filled object chamber changes a kaleidoscope: slower motion, softer edges, deeper color, the air bubble, sealing and shipping - and how to choose.