Instructions:

 

1. Print out the guide
   you need onto A4 paper
    

2. Cut along the dotted lines
    

3. Fold the strips to a 90° angle so they sit flat on the keys
    

4. Place on the piano or keyboard  standing behind and at the back of the keys, with the coloured strips sitting on the keys

 

Note: This template will only fit onto the keyboard in certain places that correspond with the correct key positions.