Activating Adhesive on Pre-Pasted Mural Wallpaper

Mural panels standing on edge are cut, sequenced, staged, and ready to be pasted.
The panel lying on the floor will be my last strip, and will need to be measured and trimmed narrower before it’s ready to be pasted or hung.

I use several different methods to paste pre-pasted wallpaper, and you can do a Search here to read more.
But for today, I’m using the tried-and-true historic method of running the strip quickly through a water tray .
At the top of the photo, several strips have already been submerged and pulled through the water, then folded pasted-side-to-pasted-side. This is called booking .
Booking allows the adhesive on the back of the wallpaper to absorb the water and become activated. And it allows the wallpaper substrate to absorb moisture, expand, and then contract a little.
This method can sometimes get the material a little too wet, which can lead to over-expansion and then bubbles on the wall. That’s why I’ve placed the booked strips at a slant and over the bucket – so excess water can drain off.
Usually I paste and book one strip and then paste and book the next strip. While I’m hanging one, the second one is booking and waiting its turn to be hung. But with this water tray method and certain brands of pre-pasted material, such as Anewall , York , or Sure Strip , the paper sometimes gets so wet that it needs more time to dry before attempting to hang. So I’m pasting more strips at a time, so they can be drying out a bit while I hang the first strips.
There’s a bit of a risk to this, which is the potential for the paper to over-expand as it sits wet waiting to be hung. Then once it’s on the wall and starts to dry, it can shrink. All wallpaper shrinks when it dries. But if it has expanded too much, then when it dries and shrinks, you can be left with small gaps at the seams. Again, gaps are common with all wallpapers (most all), but can be exaggerated when dealing with over-saturated pre-pasted material as it shrinks.
Back to the method … You see the water tray, filled 3/4 full with clean water. I’ve set it on towels, which are in turn set on top of a thick plastic clear shower curtain. And that’s on top of my usual dropcloths, which are absorbent on the top (blue) side and water-proof on the underside. All this keeps any splashed water from getting onto the clients’ floors.
I also sometimes set the water tray in a bathtub, with towels set over the edge of the tub and on the floor.