Whether you use PVA glue, acrylic medium, or methyl cellulose, wet glues have their own problems and their own great uses.
I always wanted to use glue sticks, but I just don’t have luck with them. They aren’t precise enough, and for some reason, they don’t hold well over time. If they work for you, great.
So, here’s what I’ve found out about using wet glues.
Buy them in big bottles and transfer them to smaller squeeze bottles. Label them by writing on a piece of tape and putting the tape on the bottle. Wipe the rim of the big bottle carefully with a wet cloth so you can open it again.
Invest in parchment paper. The kind cooks use in the kitchen. Not waxed paper, not plastic wrap, or freezer paper. Not parchment from an art store. Kitchen parchment paper. I bought a giant stack and use it in pieces about 5 inches x 8 inches, or, if I am working on larger pieces, enough to leave a one-inch margin around the piece I’m working on. I tear up an entire stack, and work on top of the stack. More on that in a minute.
The trouble with glue is. . .well, it’s wet and sticks to everything. Including your clothes and skin. Wear an apron, and have a wet cloth handy. Once most glue gets on your clothing, you’ve got a piece of work clothing. If you jump up and wet down the clothing right away, you might save it, but it’s a hell of a way to spend an afternoon. Wipe your hands on the wet cloth frequently. Pulling glue off your skin is painful, wrecks a manicure, and may not come off in one piece. Walking around looking like a leprosy victim is not priceless, it’s creepy.
PVA, acrylic mediums, and methyl cellulose can be thinned with water. I use distilled water in a spray bottle. Rather than thinning the whole bottle, I thin small amounts–about as much as I’ll use in 10 minutes.
Use the parchment paper as a glue palette. I squeeze a puddle of glue about the size of a quarter on a small piece of parchment. To thin it, I spray distilled water on it. I quit using tap water when I sprayed the water into the glue and a week later, there was mold on the glue. I quit using boiled water when I lived in hard water areas and the minerals in the water streaked the medium and showed when it dried. Distilled water avoids all sorts of problems.
Don’t scrimp on parchment. I use a 1-inch brush to cover a large area, and run the brush over the edges to get a good seal or to serve as a base coat on paper. I do one side, and pick up the parchment and move it aside. Most paper won’t stick to parchment and you can let it dry. Do NOT try to pick up the paper and use the parchment again. Wait till both are dry. You can re-use the parchment then. But while it’s wet, you will just transfer glue to the wrong wide, smear your work or mess up your surface. I’ve read the tip about using a phone book, but phone book ink smears and transfers, and it’s not what I want.
Most lighter papers will curl if you apply glue to one side. Particularly if the grain is running long. Use acrylic medium on one side, let it dry, then flatten it with your hands and coat the other side. After that, you can use watercolors, acrylics, and more glue and the paper won’t curl and ruin your project.
Acrylic mediums can be used as a base coat, a top coat, an isolator (coat the piece to be glued down on both sides, let it dry, then glue down), and a glue. You can coat isolated areas in matte and others in gloss for wonderful effects. If you want a gloss finish, don’t apply gloss over matte. You can apply matte over gloss to take the shine down.
If you are a collage artist, and have windows in the image, coat the glass part of the window image with gloss medium, then use matte or satin on the back for glue. The glass in the windows will shine, giving it a real effect.