Final answer:
The best practice is to use a measuring device to determine the thickness of the product.
Step-by-step explanation:
When you are unsure of the thickness of a product that has not been marked on the packaging and a customer is in a hurry, the best practice is to use a measuring device to determine the thickness of the product. You can use a ruler or a caliper to measure the thickness accurately.
For example, if you are wrapping a book and need to know its thickness, you can use a ruler to measure how thick the book is. This will ensure that you choose the right size of wrapping paper and provide a neat wrapping for the customer.
By using a measuring device, you can provide accurate information to the customer and avoid any mistakes or delays in the wrapping process.