@Libbpatt 

You would have to tell me more about your process.  IMO the card shouldn't be either an inventory or a service item because you aren't selling the card, you are selling a service.  Based on your description, it's my opinion that the card is just an expense for your business like shopping bags at a grocery store because, again, the card is not the product, the service (use of the machinery) is your product.  Just my $.02.