I am currently working on a project to make a story creation device. The idea is to have a mini thermal printer (Adafruit) connected to 3 RFID readers. The device would generate a story based on the order in which an RFID is placed on the device. The printer would then print out a small story and comic strip based on the order of the RFIDs. It's meant to be a kids toy that will allow kids to generate their own simple story based on the character choices they have and then they can colour in the printed story. If this is unclear please let me know.
I have been testing out my thermal printer with an Arduino Uno and one RFID reader it copes fine printing text but images even very simple ones don't print out with very good quality. I am only looking to print line drawings but my question is would I get better results using an Arduino Mega or a Raspberry Pi or are there better ways to do things with the Uno? Ideally I would like to stick with Arduino as a Raspberry Pi is something I've not worked with before.
Any advice or guidance on the hardware I should be investing in would be greatly appreciated.