In layer costing, a layer is the quantity of an asset item received or grouped together in inventory and sharing the same costs. Available inventories are made of identifiable cost layers. Inventory layer.Click to see full answer. Moreover, which method has the most layers of inventory?There tend to be more inventory layers than under the FIFO method, since the oldest layers may not be flushed out for years. Weighted average method. what are the four merchandise inventory methods? According to our text, there are four different methods to determine inventory costs. The methods are specific identification, first-in, first-out (FIFO), last-in, first-out (LIFO), and weighted average cost. Each of these methods are capable of determining approximate flow of inventory costs within a business. Also to know is, what are inventory methods? The method a company uses to determine it cost of inventory (inventory valuation) directly impacts the financial statements. The three main methods for inventory costing are First-in, First-Out (FIFO), Last-in, Last-Out (LIFO) and Average cost.How do LIFO layers work?A LIFO layer refers to a tranche of cost in an inventory costing system that follows the last-in, first-out (LIFO) cost flow assumption. In essence, a LIFO system assumes that the last unit of goods purchased is the first one to be used or sold. Each of these purchases represents a different LIFO layer.