Conspicuous Jamb Liner
It’s not hard to spot the lamb liner in this picture, even without the circles. The problem with typical jamb liners is that, not only can they be seen above the lower sash when it’s closed, but also around the perimeter of the lower sash. If the window sash are painted white, it’s not a problem, but the darker the color, the more the jamb liners stand out. Because the jamb liners in most contemporary windows also serve as compression seals and must mate firmly with the sash edge, if they were painted, it would scrape right off the first time the window is opened.
Inconspicuous Jamb Liner
The Magnum jamb liner is invisible! The liner in this picture was painted the same color as the jamb and trim so it just disappears. Since the weather-stripping, which is hidden on the edges of the sash, is the only thing that makes contact with the jamb liner, the jamb liner can be painted any color you choose, and it won’t rub off with use. If your windows are stained, your local paint store can match the stain color with the proper latex paint, so even then the jamb liners become inconspicuous.