Is it still illegal to make a t-shirt with the cover 写真 of an album, even though I'm not selling it または anything?

So I'm thinking of making myself a G-DRAGON Heartbreaker (picture below) t-shirt (not to sell または anything. just to wear.) nut I've been told によって someone that it's illegal, although I'm not planning to sell it online または anything (so I don't see why it would be illegal)
so...uh, help? ^^;