Preventing White From Showing At The Seams

When wallpaper gets wet with paste, it expands a bit. And when it dries, it can shrink just a tad. That teeny gap at the seams can expose the wall underneath it. This can happen even with the non-woven materials, which are supposed to be dimensionally stable.
In addition, manufacturers usually print on a white substrate, so sometimes you see the edges of the paper at the seams, too.
All this is much more noticeable on a dark paper, such as here.
One thing I do to prevent / minimize this is to strip the wall with dark paint under where the seams will fall. So even if a seam opens up a bit, you’ll see dark, not white.
Since non-woven wallpapers don’t expand (much), it’s easy to measure the width of your strips and plot where the seams will fall, use a level, and then apply the paint.

I use plain old craft paint from the hobby store. I use a scrap of sponge and dip that in water (in my orange bottle cap) then into the paint, and then run my stripe down the plumb line I’ve drawn on the wall or used my laser level to shoot a vertical line.
It’s important to not get the paint too heavy or thick, because the wallpaper paste may not want to grab ahold of paint like it wants to hold on to a wallpaper primer. And definitely don’t use a gloss paint.
Be sure that it’s good and dry before you hang the wallpaper. A heat gun will speed things along if needed.

Not pictured, but you can look up other posts here … I also take a bit of chalk of a corresponding color and run it along the edge of the wallpaper to cover up that white edge. It’s important to apply the chalk from the back, to avoid getting any on the front of the wallpaper. Some colleagues use water markers, pencils, or gouache paint. Whatever you use, do not use anything with oil-based inks or colors. These will bleed and stain your wallpaper.
Chalking the edges is more important than striping the wall, IMO.

This pattern is called Allure and is by Graham & Brown , a brand I like a lot.

Tags: allure, bleed, chalk, craft, dimensionally stable, edges, expands, gap, gouache, graham & brown, heat gun, ink, laser, level, marker, non-woven, oil-based, paint, paste, plumb line, primer, seams, shrink, stain, wallpaper, white