Read the maker’s exact scale
The UK maker product record labels Ultramarine lightfastness Excellent, and the Cotman chart shows the Ultramarine row withPB29 and a lightfastnessI entry. The chart also uses a separate permanence field. The journal keeps those source fields distinct rather than treating all symbols as one interchangeable grade.
The rating is not our experiment
No sunlight exposure, accelerated ageing or display test has been performed by this site. A maker’s rating does not establish a fixed number of fade-free years for a finished painting. Substrate, other colours, conditions and the exact test scope cannot be replaced by a single general promise.
A useful order check
If a purchasing brief requires a documented colour-specific rating, look up that exact selected colour rather than adopting a set-wide marketing headline. The other eleven half pans do not inherit Ultramarine’s individual row. Unknown ratings should remain unknown until their own source is checked.
A concrete order check
A workshop purchase brief that requires a colour-specific rating should carry the actual scale beside the entry. Writing only “I” loses the scale name and source context. Writing “permanent” beside it does not create a second independent test. Keep each documented field as a separate attributed statement rather than converting it into a guaranteed display lifetime.
Next decision
Keep the manufacturer’s current chart and actual tube or pan label with the record. The site does not assign an independent quality grade or turn a retailer’s “exceptional” category into a scientific result. Independent art-material and substantive-content review remains pending.
Sources & scope
Checked November 5, 2026. Manufacturer and retailer references support the specific statements. Dated displayed prices are not final checkout quotes, performance rankings or performance testing. This shopping reference does not replace the exact product label or retailer instructions. Current received labels and independent art-material/chemical/content/commerce review remain pending.