- maximum size A4 (29,7 cm by 21,0 cm) - art-work in black white and middle tones - techniques are free - must be suitable for all ages * Exhibition after oct. 2017. All contributions will also be shown at * please write your name, address, country and Email-address Send to: Black and White Jonckbloetplein 24, 2523 AR Den Haag, The Netherlandsby Alex Witter - Mail Art Calls