For: Art pad or art journal fun, trying certain things out quickly, more experimental work.
Test: Test each brand and softness of charcoal pencil if you find that appropriate to do so.
Air Pockets and Wrinkling: Yes. I worked them out. Some fine wrinkling remained. The paper didn’t tear accidentally though.
Smearing of Charcoal: Yes. Minimal but it did happen.
How and With What: I took some Canson Translucent Sketch Paper, made a charcoal sketch of a previous drawing of mine, took some canvas (paper in this case), laid a coat of Liquitex Gloss Gel down, put the charcoal sketch on top while the gel was still wet, laid some more gloss gel down. I had fixed the sketch to the canvas paper.