If you charge your customers to clean, repair, refurbish, recondition or restore jewelry and other merchandise, you owe retailing B&O tax, and you must collect and report retail sales tax on both labor and materials.
If you deliver the repaired items outside of Washington, you do not owe retailing B&O tax, and you are not required to collect and report retail sales tax. You must keep documentation to show that you delivered the items out of state.