Paint Overlapping external glass (painting windows)

[Sl6]

When painting external window frames should one extend the paint from the putty onto the glass? I imagine that if one did then it would provide additional protection for the putty which would be a good thing?

If doing so how far should one go? 2-3mm?

I also imagine that there would be no excuse for leaving a solid strip of paint on the windows that wavers between 10-15mm wide?

I also would appreciate any tips on fixing it - though I imagine they all involve the use of a sharp blade.

As you may infer we are disputing the quality of work that has been done.

Many thanks.

 

[Chri5]

On sashes and any wood to glass I tend to go 2-3mm on to the glass. The idea being that water runs off the glass and off the paint. If the paint stopped on the putty, if the putty moves away, it would allow water to get behind and rot the window wood and / or blow the putty when the water freezes and expands.

The exception to the 2-3mm is what overlap has been done on the inside, if that's 6mm and yellowing, it would be daft to go 3mm outside and see the yellowing from the outside (that's on the inside).

15mm is far too much and restricts the light coming in too much.