Stephen Hull wrote:

In message lgate.org
"Lawrence Zarb" wrote:

3 months ago I painted a south facing window-cill with Dulux Brilliant
white non-drip gloss. Now I notice that where there are items on the
window-cill the paint has discoloured underneath them...Has anyone got
any ideas as to why??


[snip]

Sounds daft and I can't explain why but areas kept in the dark appear
to turn yellow very quickly indeed.


Oil-based paints need UV to *not* yellow; sounds illogical (at least to
me) I know, but we have a bookcase in the corner of the room with some
books on top. Where the taller books covered the dado rail the paint
yellowed. Removed the books and it turned white again!

Read this reply by Max Bone (of Decorating Direct) in this very NG

http://tinyurl.com/ms4p

Paragraph beginning, "This is an alkyd formulation...."

I don't think Dulux is quite as good as it used to be, if it ever was
that is.


Steve.