Countless bathroom debates get boiled down to preferences, but some positions are actually backed by science. Like the debate between disposable razors and safety razors. There’s no denying safety razors have sharper blades, last longer, and are more affordable (and they don’t pollute the environment with excessive plastic).

Of all the bathroom-related debates, toilet paper is one of the biggest. People argue over every aspect of TP, including what brand to buy, how much to use, how to hang it, and even how to wipe. The biggest debate? Where to put the loose end: over, or under the roll. 

Hanging toilet paper: over or under?

Thanks to research studies revealing office restrooms to be germ factories, it’s been confirmed that hanging toilet paper in the “over” position prevents the spread of bacteria. It’s a beautiful day when science confirms what you’ve known all along: hanging toilet paper in the “over” position is correct.

In 2011, researchers from the University of Colorado used high-tech genetic sequencing tools to test twelve Colorado public restrooms. What they found is disturbing. The researchers “identified 19 groups of bacteria on the doors, floors, faucet handles, soap dispensers, and toilets… many of the bacteria strains identified could be transmitted by touching contaminated surfaces.”

One of those contaminated surfaces happens to be the wall behind a roll of toilet paper loaded in the “under” position. Loading toilet paper in the “under” position causes the free end of the toilet paper to rest flat against the wall. When grabbing toilet paper in this position, a person is likely to brush their hand against the wall and pick up existing bacteria, while leaving a deposit of additional bacteria for the next person to pick up. Gross!

Loading toilet paper in the “over” position makes it easier to grab without touching the wall. People will only touch the toilet paper they’re going to use. Then, hopefully, they’ll flush it.

But wait, there’s a messy catch

Chances are, you’ve seen shredded toilet paper all over the floor in otherwise clean establishments, causing you to wonder what kind of animal was in there before you. Was someone having a bad day? Did a couple of kids throw a party in there while their parents were waiting patiently outside? What’s going on with all the shredded toilet paper?

Shredded toilet paper all over the floor is usually carnage from the struggle to get improperly loaded toilet paper to roll. Unfortunately, most commercial toilet paper dispensers are designed to work only when the toilet paper is loaded in the “under” position, and employees load them incorrectly – err, relatively speaking. Now you know why you have to fight so hard just to get three squares out of most gas station toilet paper dispensers.

Most commercial dispensers are stamped with instructions to load the toilet paper in the “under” position, but good habits die hard, leaving employees with the task of cleaning up toilet paper confetti at the end of their shift. They don’t realize the mess can be avoided by loading the toilet paper rolls the other way.

Buying toilet paper: 1-ply or 2-ply? Strong or soft? Mega or Super Mega?

People tend to use the same amount of TP whether it’s one-ply or two-ply. One-ply toilet paper is more expensive, yet tends to last twice as long.

If you’ve got a septic tank, one-ply toilet paper will break down faster than two-ply, but is there a difference between strong and soft? What about Charmin’s gazillion options like strong, soft, and gentle? Will Mega rolls or Super Mega rolls last longer? It probably doesn’t matter too much, as long as your TP doesn’t leave you full of fuzz.

Using toilet paper: Wet or dry? Flush or throw away?

Dry toilet paper is mostly an American thing. From a hygiene perspective, it doesn’t make sense unless paired with a bidet or wet wipes. For instance, if you use a traditional restroom in India that hasn’t been Westernized, you won’t find any dry toilet paper (it’s forbidden in the main sewer system). Instead, you’ll get a hose with a spray nozzle, and yes, you’ll probably want to take off your pants first.

In America, wet wipes are the next best thing to a hose, but there’s a dark side to wet wipes.

For households with kids in diapers, it’s no big deal to put used wet wipes in a diaper pail. However, consumer researchers found that most adults are reluctant to put used wet wipes in the bathroom trash can. In response, manufacturers created flushable wipes to solve this problem. Except, flushable wipes cause a bigger, stinkier problem – they clog up city sewers and there are now ordinances that prohibit residents from flushing any kind of wipe. Despite what the labels say, flushable wipes aren’t so flushable after all.

The solution? Get a hands-free, motion activated trash can to dispose of used wet wipes. A small one will cost you about thirty bucks at Walmart, and the battery will last for months.

Wiping: you’ll never get it all with dry paper

Let’s face it, dry toilet paper isn’t going to get your bits completely clean. The best way to use dry toilet paper is to dry off after using wet wipes or a bidet.

If wiping feels like you’re scraping peanut butter through a carpet, a little manscaping and some wet wipes will solve that problem.

Buy the toilet paper you like and spare no expense

All things considered, buying toilet paper shouldn’t be complicated. Aside from thickness, toilet paper styles aren’t that different. It’s not like buying beard oil where you need to make sure the scent is something you want to smell for the next twelve hours. Toilet paper has one use and then gets flushed down the toilet never to be seen again.

Science can tell you how to align your TP, but it can’t tell you what toilet paper to buy. Only you know what toilet paper works the best. So, go ahead and splurge on toilet paper – your butt deserves the best.