You probably all know about the trading card game "Magic the Gathering"©
My brother is playing it (I used to but stopped about 10 years ago), and recently show me some interesting altered cards. So ask me : what are altered cards ?
Take a normal card, paint on it (either to adds details or enlarge the size of the illustration or replace the original illustration), you get an altered card.
So he convinced me to give it a try, I took a basic mountain card (original illustration by John Avon), and continued the picture on the whole card instead of just the upper half of the card. I left unchanged the orignal illustration, the black borders and kept the name of the card so it can still be played in tournaments. I painted all the rest with acrylic paint and an tiny tiny brush.
Card size is around 60mm x 85mm.

For a first try I'm quite happy about the result, given I didn't touch paint for 8 years.