How to determine whether Blu-ray disc is HTL or LTH?

Here's the best way I've found:

1. Determine the manufacturer code and media type of the media. On Linux, I used cdrecorddev=XXX -atip | grep -i 'manufacturer\|media type', where XXX is the code for the Blu-ray burner as listed by cdrecord -scanbus.

2. Look up the manufacturer and media type codes at http://www.blu-raydisc.info/licensee-list/discmanuid-licenseelist.php . The table on that site identifies "recording type" (i.e. HTL or LTH) and also write speed from these codes.

With image burning software. ImgBurn forinstance.

In Imgburn main menu just click on anything writing related. For example, "Write image file to disc"

Now a new window pops up

Please check that you have the correct burner selected in the left hand side, if you have more than one disc burner.

Scroll down on the right pane, and you find the info under "Recorded Mark Polarity"

In august 2016 it looked like this: ImgBurn Screenshot