Traditional ink papers are quite difficult to handle because they are absorbent delicate and and some of them are translucent. In the early days of using papers like this when I was first back from China, along time ago, I made the mistake of using glues which coloured over time, and this is problematic, so now whem sticking any kind of light paper my bet is with flour paste.. This is made by mixing flour with a little cold water, then adding more water and heating and stirring to form a paste, once the paste is cooked add more water until the paste is milky, and seive then stand to cool before using.
While the glue is cooling, collect your tools, a second water only brush or squirty bottle filled with water, masking tape, cutting board,
Tape one end of the heavier in this case Fabriano paper to a cutting board using masking tape and either spray or lightly wet the back of the paper with a brush
Fold it back with the hinge of the tape and leave the space clear for the original work, leave the water to soak into the Fabriano paper for a little while while the paper relaxes
So this is the top , turn the paper over so the back is up
Leave to dry with the edges weighted