Sparked by this question, I wanted to discuss the most efficient and also the easiest ways of thermally insulating the heat block of the hotend.
I have seen Kapton tape insulations as done here with a very conclusive resumee about its usefulness.
In the links of the named article, a method with insulating material from a heatbed is described, however without giving quantitative results.
Additionally, I know that in the guys over in the german reprap forum produce their own silicon covers for the heater block. As I understand there is a large spread between people's reports, from 'almost negligible' as insulator (but helpful for other things) to very useful. No quantification, though. Also, these seem to come with a certain amount of effort to produce.
Are there additional solutions and/or comparisons between solutions?