The MRT (SG’s subway) is an integral part of our identity, since it’s something many Singaporeans use to travel everyday. There can be a stamp collection with a stamp for each MRT line, like East-West, North-East, Downtown, Circle, etc. There’s exactly 6 MRT lines right now so it’ll be nice to see a collection on that, especially since SG only has one. It can be colour-themed too, since each line has a different colour.