India Post has issued different stamps on same or similar subject on different Occasions and Events. The collectors with creativity have made covers with combination of  stamps of such similar Occasions and Events duly cancelled on respective dates. Such covers show the creative efforts of the philatelists.

Here on this official cover, stamp of First Triennale, New Delhi dated 31-3-68 and  stamp of 6th Triennale - India 1986 issued on 22-2-86 are combined on one cover of 31-3-68 with cancellations of respective dates.