One way of cutting down on weight and space when your travelling is to paint on gessoed paper or unstretched canvas. Another benefit is that you can just toss these in a box when dry, saving on storage space. If you have a painting that you like well enough to frame, you can mount it easily on hardboard with this method.
By the way, it should go without saying, but I have to emphasize that the paper you use to paint on must be acid-free and archival. As a further safety step, seal the paper with PVA before painting to prevent migration of linseed oil down into the paper. Best, however, would be to use canvas rather than paper. In the unlikely event you have to unmount a painting by reversing the glue, paper may be damaged in the process. Canvas should unmount without any problems.
For additional details, visit my blog post on this method at http://mchesleyjohnson.blogspot.com/2012/08/mounting-finished-paintings-on-paper-or.html
Board used: MDF or “Masonite”, preferably untempered and not tempered
Glue used: Lineco Neutral pH Adhesive
Post time: Apr-13-2018