The Princess Ponies first appeared in the My Little Pony line in Year 5, with a second set released in Year 6. Instead of the painted-on symbols, each Princess Pony had a raised medallion with a jewel inside. The ponies also had tinsel in their hair.
The first set of Princess Ponies came with Bushwoolie characters, a glitter star hair pick, damsel hats with ribbon, and a glitter wand.
The second release of Princess Ponies didn't come with Bushwoolies or damsel hats. They came with star picks, wands, and a crown-shaped barrette. They also had short tufts of tinsel hair on top of their heads.
In Year 7, a line of Princess Brush 'n Grow Ponies appeared. These ponies had jewels on their foreheads instead of as their symbol, and only had tinsel in their manes. Their tales could grow long like other ponies in the Brush 'n Grow line.
A final set of Princess Ponies was released in Year 9, this time with long eyelashes and regular painted-on symbols instead of jewels.
The metallic medallion symbols of the Princess Ponies were made of plastic, so they were easily scratched. It is also common for the metallic finish to peel off.