The most common question we get asked here at Colin Bradley Art (almost on a daily basis) is regarding Fixatives.
Generally it is thought necessary to fix pastel work to contain the loose pastel flakes from the pastel paper and to stop the pastel from smudging. In the case of pastel pencil paintings in my opinion fixing does in fact spoil the work. This is because pastel pencils are finer and therefore more translucent than the soft pastel medium which has a higher pigmentation. I explain this to all my students and recommend that they do not use fixative for the reasons stated.
Applied correctly pastel pencil work adheres better to the pastel paper than soft pastel and as a result there is no flaking problems. Of course without fixative being applied they are more susceptible to smudging but as long as care is taken these can be framed and mounted successfully. If you were to see a pastel pencils painting before and after being treated with fixative you would readily see the difference between them, the unfixed painting has life and vibrancy whereas the fixed painting is dull and lifeless.