I had an office job for a few years. An office job that generated a lot of paperwork. There was lots of printing and reprinting and copying and even faxing. But it wasn't a big deal because whether I was working out of a real office or a construction trailer, the equipment was nearby. If I needed something, the supplies were right there.
The first strange adjustment to teaching is the sheer size of a school building. You ever been in one lately? Huge. Print something? It's a 100 yard walk to the printer. Did it print wrong? A 100 yard walk to your room and then back to see if it worked this time. Need to copy something? Upstairs. Forget something to copy? Walk to the stairs, down the stairs, down the hall, find the thing, down the hall, up the stairs, walk to copier.
Need to talk to a colleague? Better be worth the three flights of stairs. Some school days I may only interact with two adults just because everyone is so far apart.
My first and second year I often found myself in a situation where I ran out of copies or needed to print new copies in the middle of a lesson. The process of printing whatever it was, finding a neighbor to listen for danger, walking to the printer and back could eat 5 minutes of class time.
Then my third year I adopted the "never again" mindset and began a small supply hoard in my room.
Seriously, buy your own printer. I know you think the laser printer in the math office is great and it seems really fancy and expensive, but it's not. Like, you have no idea. $100 gets you black and white laser with a toner cartridge that will last two years.
Even color is getting affordable. This year I went color and it's been very beneficial.
Colored paper entered my life in a big way during my third year. I began cranking out posters and other displayed work once a grading period. I easily used a few hundred sheets a year. The department had a supply that kept up with demand, but either my ideas are spreading or it's being used in other ways because our year's supply is already gone. Posters are harder to come by as well. A paper shortage is not getting in my way. Reams are $8/each and 500 sheets could easily last a couple school years. This is a no brainer classroom investment.
Oh, and a full backup of toner just for kicks. And tennis balls. All the tennis balls.
Student Facing Consumables
A classroom built around a student constructed notebook goes through a lot of materials. Assignments need to be glued, taped, or stapled. Things need to be colored. Straight lines need to be drawn. For that, there's the student supply table. Everything on here is intended for student use.
Rulers, markers, scissors, tape, staplers, colored paper scraps and a hole puncher. The rulers are the 0.99 variety from Office Depot. Get wooden ones. The markings on the plastic ones rub off over time. Every August I buy two packs of new markers and put them in the bucket. Throughout the year kids are free to toss markers that are no good. Next is glue sticks. I ordered 100 through bulkofficesupply.com for 0.50 each. And these are big glue sticks too. Triple the size (0.74oz) of what you normally get (or what we get through our district supplier). Scissors are department furnished though I have 30 in reserve I just bought as well. And who needs three staplers? Teachers need three staplers. Don't skimp here either. Nothing gets abused like a classroom stapler. It needs to last. Sadly even at $20/each I see a stapler last a year school, maybe one and a half.
In the end, I invest in this stuff because I demand control. Eating 5 minutes of class time to walk to a printer is no longer ok. Having 30 kids wait for one stapler to be passed around is not ok. Scrapping a project because there are no materials is not ok. Paying attention to the logistical demands of your classroom payoff in huge ways and shouldn't be underestimated.