Add a Field to print on invoices.php

I created a field in the Products table and I need to access it to print or append to the model number when the invoice prints.

It is a bin number for the product number to assist a packer in finding a product easily. When I edit or enter a new product I have an input field to enter the bin number, it is all working well, updating the database.

I just need to print this bin number on the invoices.php for the corresponding model number for what they ordered.

Can anyone point me to a solution?

I added a new field to the orders_products table with same name as the products table (I call it products_bin). Now I need to be able to populate the products_bin field in the orders_products table from the products table when a customer places an order, then be able to access that field when I format my invoices (using invoices.php)...this has me scratchign my head...