A Boston 135 heavy-duty stapler is designed to staple large quantities of paper together. Using heavy-duty staples, the stapler has the ability to attach up to 200 pieces of paper at a time. Once it runs out of staples, more staples need to be added, but figuring out how to do so can be tricky. Unlike traditional staplers, the Boston 135 stapler utilizes a back-loading feature instead of a top-loading feature.
Position the Boston 135 stapler so it is on a flat surface, with the back of the stapler facing you.
Lift up and then push in the thin metal latch located on the black staple-holding box. As you do this, the staple box will be unlocked and will release toward you.
Insert heavy-duty staples into the staple holder, pushing back on the spring that feeds the staples forward until the staples are loaded. Gently let go of the spring.
Slide the staple-holding box inward until it locks into place in the stapler.