I have been given some oil pastels as a present but am finding it difficult to get any advice on their use. I would like to know whether a finished picture should be varnished when dry in the same way as an oil painting. I have two paintings I finished a week ago and they still seem to have some sticky areas.

Cathy Gosling replies: HarperCollins has published a book in the Learn to Paint Series: 'Oil Pastels' by Jacqueline Black. This offers some very helpful ideas on materials and equipment, basic techniques and methods of painting with this exciting medium. Jacqueline suggests using a fixative spray as for ordinary pastels - several light coats will help fix your work and make it less likely to smudge. When storing unframed work, put a thin sheet of paper between each one to protect it.