Hello,
You should create an Item, pens, and use the Inventory adjustment (or POs) to add your stock of pens.
You can use manufacturing simple assembly to create your various boxes. And for every box you create a bom. Then create work orders as you need them.
Every time you create a work order, the pens are reduced from stock and the new box is increased.
If you have a Training Co. you can experiment with this until you are satisfied.
/Joe
