In 1980 I would have sworn by Sadolin PX65.
Unsurprisingly, the old adage "Sadolin poisons the world" seems to have caught up and it doesn't exist anymore.
I need:
1) Exterior grade;
2) Microporous - as in easily overcoatable, not forming a thick surface film like paint.
3) Coloured - dark brown, exact shade not important.
It's for gutterboard and soffits and window frames - mixture of red cedar (which needs no real protection, so just to match the colour) and treated softwood (for colour and protection).
The only product I "know" is the Ronseal stuff, but I'm not convinced it's the best for the job...
Cheers!
Tim