Most tubing in this review has a bend radius in the 1.5" to 2" range, which of course translates into bend diameter of about 3-4".
Perhaps coincidentally, this also corresponds to the distance between barbs on NB/SB blocks on a typical Intel motherboard.
Both brands of Tygon are similarly clear but the R-1000 does have a slightly yellow hue.
In the next picture, you can see the difference in clarity in the medium sized tubing.
The next picture shows the 1/2" thin-wall tubing and 7/16" tubing selection.
Master Kleer after 6 months in a loop: The smaller tubing samples all exhibit the same clarity attributes of their bigger counterparts...The tubing reviewed is pictured below (with larger tubing on the left and smaller on the right).Note that Tygon, Duralene, and even Master Kleer are made by Saint Gobain Performance Plastics.Since the point at which a tube starts to kink is a very subjective measure, I decided to take another more objective approach and allow you to judge for yourself.The collection of photos below were all taken in an identical way and then combined in Photoshop for easy comparison.
As you can see with this tight radius, the high durometer R-3400 is able to maintain its shape without kinking while the lesser durometer tubing cannot.