Transportation of a pastel painting

Hi every, firstly I'm rather new to this forum so please bear with me if I have posted this in the wrong place, or this question has been asked before. I've been painting with watercolours for many years completing predominantly animal and bird commissions and works to sell on-line. For the past few weeks I've been studying pastel videos on YouTube, SAA and the Painting and Drawing Channel and have become very interested in trying out this medium. My preference would be pastel pencils due to the detail I like to try and achieve. Now because I sell most of my work on-line I was wondering how delicate a pastel painting will be in the post. I know the some artist use fixative sprays but have also read on here that they can dullen the painting which I certainly wouldn't want. I wouldn't wish to risk sending my work through the post in the chance the painting becomes smudged or damaged in some way or other. I currently sandwich my paintings(unframed) between two sheets of card and old magazines, the line folds in the cards at opposite angles to help prevent bending, placed in a carded envelope and then a plastic postal bag covering. So as you can see I go to the extremes to ensure it gets there in one piece! This obviously works very well with my watercolour work. If a pastel painting isn't 'fixed' then do you cover the painting in a special type of paper and supply a note to the customer to be careful to not touch the painting surface? I really love the finish of a pastel portrait especially animals but this is the only thing that is currently preventing me fro buying a lovely set of pastel paintings. If anyone can shed a little light on this little query then it will help me come to some sort of decision. Thanks in advance, Paul