Sometimes you'll notice breweries using plastic can wraps, or stickers/labels around an aluminum can. This seems silly at first - there doesn't seem to be any reasonable explanation; a can plus a sticker is surely massively more expensive than just a can.
Using a stock item (a plain can) plus a short-run custom item (stickers or shrink wrap) is a quick way to get product out and see whether investing in fully custom packaging makes sense. Custom packaging is a way to tie up tons of cash and is risky if you aren't sure a product will sell. Keep an eye out for this type of packaging: it's a pretty reliable way to tell which brands and products are new to the market.