Building Airliners

You have your choice of which way to do windows. Some prefer the clear, some the black. Because the interior is generally in a "shadow" the window areas of the prototype appear a glossy black (the gloss from the window glazing). Because of the diffuse light in which a model is usually displayed, the shadow inside a model is not as dark as in the prototype.

Because the real windows are transparent, some folks expect to see transparent surfaces and prefer that.

This brings up the subject of expectations versus reality. Sometimes in modeling we want to meet viewers expectations, even when those expectations do not really agree with reality, as in overly dark panel lines and many other illusions.

I myself would prefer clear windows - the way I would do it would be to paint the interior of the jet black, or very dark gray. Then paint the base exterior color (presumably gloss white) around the windows...but just enough to make sure the window surrounds were painted, and raw plastic left unpainted for finish work on the seams.

Then I would lay a strip of Scotch tape over the window holes on the outside, and fill them with something like Crystal Clear, Watch Crystal Cement, or built up layers of Future from the backside. Then join the fuselage halves.

Otherwise, if you choose to use the black decal you can lay a strip of tape over the windows and putty them in from the reverse side. That'll help save some hand work on the exterior.