Techniques for staining and ageing paper, left to right, top to bottom: 1) No ageing 2) Tea 3) Bleach and lemon juice 4) Brasso Polish 5) Potassium permanganate crystals 6) Coffee 7) Balsamic vinegar, cooked in the oven for 10 minutes 8) Red wine vinegar 9) Burnt with match

Photograph: Flora Fricker/Annie Atkins