I use only soft pastels for my vibrant paintings.
The surface I work upon is acid free mat-board which has been given several coats of acrylic primer.
The primer provides a positive tooth to hold extra amounts of pastel and also a superb surface for making textures.
Pastels are a dry medium. They are sticks made with pure pigment mixed with a binder, the same pigments used in making all fine art paints.
To preserve the brilliant colours of these paintings they have not been sprayed with any fixative. Pastels require great care.
Once framed behind glass it is the most permanent of all mediums.
They will remain as bright and fresh as the day they were painted for centuries.