3M 77 combined with GooGone GEL (not their Heavy Duty stuff). It helps to just really wrinkle the number, then spread it out and it is barely noticeable.
Get someone to rub it on.

Sat number (good/typical ink)



Sunday Number. I stopped wrinkling as the number ink was coming off - inc. on the jersey. Starter ref was concerned about reading it and chief ref had no issue.


3M 77 spray - let dry till tacky (5 min)


Spray Gel on underside and wash