I love this shirt but had a little confusion with the sizing.
Ping, being an American brand is sized in American sizes, so according to the guidance a USA medium [M] is a UK/EUR large [L], except it is not quite there. I would be more inclined to say that a USA M is more of a M/L UK/EUR. Similarly the USA L is more L/XL UK/EUR. So for comfort if you are a UK/EUR L normally go for the USA L UK/EUR XL
Unfortunately I have used my shirts once already so unable to return them. Just gonna have to loose weight!
Anyway its a great shirt just make sure that you get the right size.
Happy Golfing!