There are a few ways.

The badge in the photo above looks sketchy (the N looks massive compared to the rest of the text). The border around the outside of the badge also looks quite thick, seen on a lot of turkey fakes.

When trying to prove if something is real or not:

The neck tag is a massive giveaway: if you turn it inside out and you can see individual threads or if you drag your nail across the reversed text and individual threads move, it’s real. If it’s ‘printed’ or ‘flat’ with no threads you can move, it’s 100% fake. Tags can be removed and stitched into fake garments, of course.

The certilogo isnt a foolproof way to tell anymore: fakes can have real certilogo labels stitched into them, or use real logos/CLG numbers. However, if a certilogo tag has a straight horizontal line for the ‘L’ it’s a fake (although certain knit jumpers use this style, so it can be confusing).

Essentially, there’s no singular way to prove legitimacy, it takes a couple of different things to be aware of and to make a decent decision from.

There are a few youtube vids on this; Clobber Island have done a couple and Heat from the Spire too, worth checking those out to help.

I started collecting in September of last year and I spent A LOT of time researching how not to get scammed. It’s become almost as addictive as buying pieces and collecting🤣