There are two methods, probably more. One involves the artist wetting the paper and letting the water drain off. An acrylic gel medium is spread with a squeegee all over the board and the paper is placed on the board and smoothed down with clean hands starting in the middle and working his way to the edges to get out all bubbles.
The second way involves no artist time but spending more money. Many good framers use an archival glue and big press and can secure the paper that way.
Then, you paint as usual and then varnish with many coats of a UV acrylic spray. No glass is required in framing. Always test first, however!