During the centenary celebrations to honor Saint John of the Cross in 1991, the official Philatelic Bureau in Malta issued a stamp in honor of the Saint.
A limited number of First Day covers and separable postage stamps, most of them stamped on their first day of issue are available.
Though their monetary value is negligible (less than 10Euros), some Carmelites might be interested in acquiring them for sentimental-religious reasons. These are collectors’ items.
I am including a copy of the potage stamp. If anyone is interested, please contact Father Pius @ pius@cheerful.com.