John England fabrics are all dyed to good light fastness standards. However, over time curtain fabrics will fade, particularly if they are exposed to direct sunlight. If your curtains are unlined they will fade much faster than lined curtains. The most effective way to protect your fabric is to use a blackout lining as this will prevent any direct sunlight reaching the dyed fabric.
John England cannot accept responsibility for the fading of curtain fabrics where lining has not been used. Prolonged exposure of unlined curtains to daylight even in northern countries can be a problem.