Before ordering any woven or printed fabric, stone or wallpaper, you must get a stock cutting of it. The cutting or sample book in which you will originally have seen the material will almost certainly have been made from an earlier batch of the material. Very often, the current stock varies slightly in depth of colour, tone or background. These variations will most of the time be close enough not to matter, but when there is discrepancy and it does matter you have no official come back other than goodwill. Not checking can be very disappointing, inconvenient and potentially very costly.
The stock cutting will be from a particular roll or batch and the order quantity will be reserved for you for a specified period of time only, so you need to respond as quickly as possible and with the number reference on the order form/invoice.