Have you ever noticed that toothpaste tubes have a little colored block toward the bottom? This block may be blue, red, green, or black. If you think that this is there for the looks, you are wrong. And if you think that this tells you something about the product inside, you are also wrong.
These “eye marks” (a.k.a colored blocks) are read by light beam sensors during manufacturing, and they tell the machines on the assembly line where to cut and fold the packaging. Without these marks, toothpaste would be connected to one another, making it rather difficult to put any toothpaste onto your toothbrush.
Arrow on Gas Gauge
Next to the gas gauge of most cars that have been manufactured since 2010, there's an arrow that either points to the left or to the right. This arrow indicates to the driver which side of the car the gas tank is on. If it's pointing to the left, that means that the gas tank is on the left-hand side of the vehicle and vice versa.
Most people don't need a reminder because they get used to filling their car up and instinctively know which side of the car to pull up to the gas pump. But if you ever have to drive a new car, such as a rental car, this is a good trick.
Loop in Back of Shirt
You've probably noticed that some men's shirts come with loops in the back of them. It was the Navy who first added this feature to the backs of men's shirts. When the men were out at sea, there wasn't much closet space. In order to save on space, sailors had loops on their shirts so that they could hang them up on hooks.
In the 1960s, the fad became popular among college students who used the loops while at the gym. Seeing an opportunity for profit, the Gant company started adding loops to the backs of their shirts in order to attract their Ivy League consumers. The loop became somewhat of a status symbol.
Metal at End of Measuring Tape
Have you ever noticed the small piece of metal at the end of the measuring tape (technically the beginning)? Most likely you have, but you haven't asked yourself what purpose it serves. There are actually several reasons why the metal is there.
To begin with, there's a little slot that can be placed around a nail to help hold the measuring tape in place in case somebody isn't around to hold the other end. Cough cough, roommate. You may have also noticed that the edge of the measuring tape is a bit serrated. The reason for this is so that it's easy to mark a wall or other surface in case you forgot that you put a pencil behind your ear to mark your measurement.
Dip in Wine Bottle
Most likely, you have noticed that wine bottles come with a dip at the bottom. Have you ever asked yourself what exactly the reason is for this? Well, to begin with, the dip, which is actually called a punt or a kick-up, prevents the bottle from falling over. You know when you have a picnic at the beach or outdoors and oftentimes the plates of food fly over and there's a storm of napkins in the air? And then all that strong wind comes trying to knock your bottle over.
Well, the punt says, "I don't think so, mister." The punt also exists in order to make the bottle stronger to hold up against higher pressure if there's champagne or sparkling wine inside. Finally, the punt makes it easier to distribute steam during the cleaning process before the wine is poured in. Although wine bottles are stronger nowadays, they are still manufactured with this indentation in the bottom to keep with the tradition.