There is no self sewrvice laundry on board but you can bag up laundry and your cabin attendant will remove and return you will find the price per item on the list you complete.
We went recently on the Gem and on the first say and the last day they did an offer on your laundry which was a good deal and then we came home and not have to catch up as it was all done. (always finding a way to make money - but dont mind on this occassion).
I agree, many cruise lines do this now because they can maximise on slack days. ... Neil.
Yes there are launderettes on the Jewel I believe there are 3. There is definitely one on deck 11, although it is a bit tricky to find!