I’m about to install this last narrow strip of wallpaper . The wallpaper will not continue onto the painted wall. Because the wall is bowed and crooked , and because wallpaper expands when it gets wet with paste , it’s not possible to pre-trim the width of this narrow strip to fit the gap .
So the left edge of the wallpaper will be cut about 1/2″ wider than the gap, the excess will wrap around onto the painted wall, and then I’ll trim off the excess .
But – you don’t to get paste onto that painted wall. For one thing, it can be hard to get off. And wiping with a damp rag can mar the paint . Also, any residue left can eat into the paint and cause the surface to crackle and flake off . Sometimes this happens right away, but it can take months or even years, for the paint to mysteriously start chipping and flaking . Don’t want that!
So I use this thin , flexible plastic tape , colored blue so you can see it , to cover the paste on the edge of the wallpaper that will wrap around onto the painted wall .
Note you have to keep track of which side is up and which side is left or right. I made the squiggly pencil line to remind me which edge is to get the tape.
The tape comes 2.5″ wide, but, for this purpose, I cut the width in half.
When I use this stuff to keep paste off the ceiling, then I use the full 2.5″ width.
It’s cool stuff. In addition to being thin , flexible , and see-through , it is easy to snap apart, so no scissors needed. It comes from Japan but is available state-side here at the Wallpaper Tool Store https://www.wallpapertoolstore.com/product/blue-cut-tape/
It can also be used to keep paste off of wallpaper , in your last corner / kill point , or for a double cut / splice .
Some installers use painter’s plastic , or waxed paper or even caution tape . But this is much better and easier to use, and worth the extra cost .
Difficult to see, because trimming in this last corner is mostly hidden by the door molding . But you can see how the tape is keeping paste off the narrow bit of painted wall .
(That red line is my laser level beam , guiding where I’m going to line up the right edge of that strip of wallpaper . )
After you’ve trimmed your piece into the corner , remove the trimmed-off strip , as well as the blue tape. Make sure to remove the tape that’s behind the pasted paper , or the wallpaper won’t be able to adhere to the wall!
The Wallpaper Lady's Blog 