Dye Lot/Batch/Serial Number System
You can track dye lots (or batch numbers, serial numbers, etc.) for sold and received items by using the Require Serial Number and Require Serial Number When Receiving Items add-ons (Tools -> Add-ons), which are available in the Corporate version.
For items that need to have dye lot/batch/serial numbers assigned, you can turn on the setting labeled Require Serial Number in the Extras section when editing an item. Then when shipping and receiving this item, a dye lot/batch/serial number will need to be entered. You can then search for dye lot/batch/serial numbers in orders, invoices, and PO receipts.
You can track ins and outs for dye lot/batch/serial numbers by using the report Inventory -> Reports -> Serial Number Activity. The report will show when the number was received, and when it was sold.