Care advice
The materials I use have a good lightfast rating, but I would still advise against placing your drawing in direct sunlight.
The surface of the drawing can smudge if touched. I send finished portraits in a protective cellophane wrapper. It is best to keep your drawing in this until you are ready to frame it, and always keep away from sources of moisture.
Your portrait will come with a conservation grade (acid-free) mount and backboard to protect the drawing. Should you wish to remount it (for example to fit a specific size frame) then I recommend asking for an acid-free mount.