To identify a fake Supreme item, you should look for a few things. First, check the stitching, as authentic Supreme items typically have high-quality stitching with no loose threads. Next, look at the tags, which should be properly aligned and feature accurate branding. The materials used should also feel high-quality, and the logos should be crisp and clear. Finally, consider the price and the seller, as prices that are too good to be true or purchasing from an unverified seller may indicate a fake. Overall, if something seems off about a supposed Supreme item, it's best to err on the side of caution and assume it's not authentic.