I recently was asked to clean all the windows in St. Milburga’s Church, Wixford, Warwickshire by the church warden Mr Bryan Knight. The majority of the glass in the church is plain, diamond leaded panels. However, there is a large 5 light window with several traceries in the South Chapelh The main lights are plain, diamond leaded but the traceries contain fragments of the original 15th century glass. When I met up with Bryan to assess the job the glass was so dirty that no discernible images could be seen. I warned him that they may not clean up as well as he hoped such is the nature of medieval glass as it becomes pitted over time owing to corrosion from the acid in the rain and it can be very difficult to remove any dirt from these pits.
After 3 solid days of cleaning the plain windows, I was itching to get onto the medieval glass. Working away with a soft toothbrush and de-ionised water, it soon became apparent that the reason for the almost blacked out nature of the glass was a very thick algal bloom. And slowly but surely these wonderful characters began to emerge.