Also modern laptops and notebooks get quite hot if standing flat on the desk and the vents have to work harder than necessary. Slightly lifting it fro...m the desk helps cooling a lot.
I once found a design on Thingiverse very similar to this. I printed it and used it for a long time. The only issue I had were the tolerances. The assembled stand was quite loose and the collapsed version for transport would simply fall apart. I wanted to create a remix with smaller tolerances, but couldn't find the design any more. Therefore I designed it from scratch from the print I had. So if you think this was your design, send me the Thingiverse Id of your model and I'll be happy to mark this as a remix. And thanks again to "unknown" for the nice design idea, which i basically copied.
There are many much smaller portable laptop supports on Thingiverse (e.g. KUNA, but they are usually not very stable when you accidentally push against the laptop or when you travel on the train. The three part design seemed to be a good compromise between stability, portability and a low angle. It is easy to print (no support) and it fits nearly any notebook or laptop out there. With the reduced tolerances it is now very stable and the three parts can be clamped together for easy transport
This model is now also available on Printables
3d model print parameters
Easy print, no support required. If adhesion of your print bed isn't perfect, pin down the thin end of the side parts with an anti-warping pad in Cura (TabAntiWarping plugin)