On Mon, 21 Nov 2011 22:26:47 -0000, Andrew wrote:

The suppliers usually comment that if they are painted with a sealant
there will be no problems - but I not convinced.

Well I guess it depends on the style, I'm not all that bothered about
the staining on our recently discovered stone work.

http://www.flickr.com/photos/allsorts-60/6370269929

Which reminds me I better tell the stonemason who is going to repoint
that stonework not to clean it up too much. B-)

Cut 'n polished blocks might start to look "grubby" but where do you
draw the line between "grubby" and "patina of use"?

--
Cheers
Dave.