Depends how long it was. Appreciate the Sainsburys ones probably aren't quite long enough, but then they don't have wraparound barcodes.A long t
If the item has a wrap around barcode a long thin sticker wouldn’t be long enough to go completely round the item.
All this used to go much smoother when I was on the tills at Iceland and M&S and just knew most of the codes anyway. I didn't even need to know where the barcodes were.