Pretty simply and easy to print boxes for organizing things in your Festool Sortainer SYS 4 TL-SORT/3. There is a spot at the top of each box for a 12 mm label.  They fit well with the official versions of the boxes as well. Included a .step file so you can change / remix them as you want. 

I recommend PLA because it's good and strong, but PETG will also do the trick. 

Spectrum Light Gray PLA (RAL 7035) is a perfect match for Festool's gray