Does anyone know the reason why some English birth certificates, circa 1912-1916, were printed on flimsy paper about 5 x 4 inches(130 x 100 mm)in size. Previous and later certificates are approximately twice this size and printed on heavier paper. I had rather assumed that it might be due to a paper shortage in WW1 but 1912 is too early for that.
Were there two classes of certificate? Was one type cheaper?