Strongly recommended · for some experience
Filaween complete playlist
Why people recommend it
Thomas Sanladerer's series tests and compares 3D printing filaments with a methodical approach; recommended for judging the strength and flexibility of brands and designing your own tests.
Watch for: Filaween 2.0 for the revised test method
In their words
For deeper information on the strength of parts and materials in comparison and how to manipulate it, there are large playlists of tests made by CNC Kitchen (Stefan) and Thomas Sanladerer (Tom)
Trish on 3dprinting.stackexchange.com, Sept 2018. CC BY-SA.
There is a well known youtube channel, whose author has performed a lot of quasi-scientific testing on common brands of filament (PLA and not) where you can get an idea of the relative rigidity of the filaments.
mac on 3dprinting.stackexchange.com, Jan 2018. CC BY-SA.
Thomas Sanladerer has an excellent YouTube series called Filaween.
markshancock on 3dprinting.stackexchange.com, Jul 2017. CC BY-SA.