The first thing to know is that plexiglass is the same as acrylic glass. Plexiglas is a registered trademark, but the properties are the same. For acrylic glass there are many different manufacturers, some sell their products partly also under own name. The differences concerning light transmission, transparency and colour are mostly minimal and negligible.
If you want to drill a clean hole into a Plexiglas plate, you have to consider the following.
If you want to drill Plexiglass correctly, you have to know that you need a twist drill that does not cut, but scrapes the material. This is the only way to get a clean drill hole. To achieve this, you can drill into a concrete wall or a stone with a normal steel drill bit. The drill is then blunter and scrapes off the material as desired. If you use a sharp drill, there is a risk that the plexiglass will break or crack.
There are also special plastic drills, which you can buy here cheaply.
Tip! To cool the borehole you should use normal water with a little detergent. Simply apply a few drops to the drill hole and more if necessary
during the drilling process. Without cooling, there is a danger that the plastic will become hot and begin to melt.
Another feature is the chip that is produced during the drilling process. If the chip is crumbly, the drilling speed used is too high. If the chip is fused, the drilling speed is too low. If the speed is correct, a long clean chip is obtained.