This rebuilding project has been an adventure in learning about new building products.
The smeary stuff on the windows is the modern way to cope with the paint/glass interface. They put this stuff on, and it drys into a skin, then, after the paint is dried, make a clean cut along the glass/frame inteface and peel it away like skin two days after a bad sunburn.
If I’d only known about this magic stuff last summer when I was painting all those windows on the cottage! Well, actually, I have to finish them whenever we get back up there, so, voila! A new technique!*
* Reminder to self: ask The Guys what this most excellent Stuff is called!
UPDATE: it’s called Masking Liquid H2O, and costs something like $60/gallon, at least to our contractor, but it doesn’t take much, so maybe they sell half-pints for those of us with small jobs.