Paste as a glue size substitute.

[88v8]

So I expected to pick up some glue size in my local DIY shop but it seems to have vanished, even Dulux Decorator Centre don't have any.

I have one sheet of plasterboard to paper over with lining paper... thinking to dilute some paste... in the past, on the packets of paste it used to give dilutions for using as a size, even that's missing on the new packets... like it's a conspiracy. What are we supposed to do when wallpapering?
How much should I dilute wallpaper paste to use as a size?

 

[opps]

Solvite now call it "wall sealer" (but it has the word size on the bag)

Solvite Solvite Wall Sealer

Solvite Wall Sealer helps stop freshly plastered wall from absorbing moisture fromwallpaper adhesives as well as aiding the slide of wallcoverings for easierpattern matching. It can be mixed in 30 seconds and ready to use in 3 minutes.For use on absorbent surfaces only.

www.brewers.co.uk

I have no idea why they stopped putting the size ratio on their regular powder based paste. I guess the margins on the wall sealer are higher (?).

The everbuild powder paste still has the ratios to use it as a size.

EVERBUILD® All Purpose Wallpaper Adhesive

EVERBUILD® All Purpose Wallpaper Adhesive is a powdered adhesive which, when mixed with water, is suitable for hanging all common wallcoverings including sculptured, blown and textured vinyl, washable and heavy embossed. The product is also suitable for fixing polystyrene tiles. High tack...

gbr.sika.com

As a professional decorator, when lining over new plaster, I just use full fat paste. I roll a full fat coat- about 3 rolls wide and then full fat paste on the lining paper. Sure, I use about 40% more paste but it is an incredibly cheap product, and wet on wet ensures that on a warm summer day, I am guaranteed to have wet paste on either the paper or wall.

When working on old, gritty, lime plastered walls, I apply a coat of paste and allow it to dry, then sand it with 180 grit paper to dislodge any bits of grit pulled out by the pasting roller.