Painting next to the glass
The most common problem people encounter is not achieving a good paint edge next to the glass, but don’t be tempted to use masking tape.
It is best to paint the wood next to the glass as straight as you can. If it’s not brilliant, it can easily be tidied up afterwards using a bladed window scraper.
The paint should lap onto the glass by a fraction to seal the junction.
Order for painting a window frame
There is a strict order of painting to follow if you want to get good results.
Remove all the window ironmongery first. Tap a small nail into the underside of the bottom rail. Wind a short length of an old wire coathanger around this to form a temporary stay. This can be hooked into one of the screw holes in the frame as needed.
Many people are confused as to which part of the frame belongs to the inside and which to the outside when painting. The answer is the same as for doors, all frame edges up to and including the one against which the window closes belong to the outside.
Remember too, that the hinge edge of the opening part belongs to the inside paintwork.