How to create a 100% (spirit level) straight plane?

I experimented with epoxy resin for the first time, including a picture about A4 in size. Problem: The table is slightly crooked. The image is higher at some edges than at others. Getting the table 100% straight with a spirit level is difficult. I then tried to put the picture in water (it sank, but…

Install motherboard lying down, which ATX case?

As mentioned in the question, I'm looking for some case recommendations that allow me to install my ATX motherboard horizontally. If anyone here knows, please share their recommendations (: Here is another example, but in ITX format: CHIEFTEC | ProCube Mini Installation Demo | CN-01B-OP (youtube.com)