Percentages use beaches with at least one colour report as their total. Each beach counts once per colour, whether one piece or many were found. A beach can report several colours, so the percentages can add up to more than 100%. These percentages do not tell you how likely you are to find a piece.
Reports come from members, not a systematic survey. Some places and colours get more attention than others. More reports broaden the picture but do not remove that bias. Figures update as beaches are added or edited.
Colour names follow the choices available when adding a beach. Collectors may name the same shade differently, especially the blue-greens. Some shades, such as grey, olive green and yellow, are not listed separately yet. More colours may be added as the guide develops. Country filters include only countries with at least 8 beaches reporting colours; small samples can still change considerably with a single report.
Photos are credited individually. The small colour swatches are illustrations, not photographs of finds.
The shelf of old glass on the links to this guide is made from photos by the Wellcome Collection and Auckland Museum (CC BY 4.0), Cindy Shebley (CC BY 2.0), E.H.M.Plauen and Quercus acuta (CC BY-SA 4.0), the Metropolitan Museum of Art (CC0) and Cornell University Library (no known copyright restrictions).
