Jubilee International Stamp Exhibition was held 14–19 October 1912 at the Royal Horticultural Hall, London. The principal organisers were Fred Melville, H.R.F. Johnson and H.H. Harland of the Junior Philatelic Society."The Jubilee International Stamp Exhibition" by Charles J. Phillips in Stanley Gibbons Monthly Journal, 31 October 1912, pp. 290-297.
An "Ideal Stamp" was produced as a souvenir.
References
External links http://www.tonylester.co.uk/may-2013-auction/