Thank you very much LIGHTING UK and dbminter for taking time to look at my post and for your info. Below are screenshots of two ISO files of DVD9 projects I've made now for testing layer break position. TEST #1 - 6 x 1 hour videos of ~ 1.3 GB each, totaling 8.42 GB; chapter points every 5 minutes The layer break most likely has been chosen by Encore to be between video 3 and 4, as this is the middle of the content, and is ideal. Video arrangement in Encore: [video 1 ~1.3 GB] [video 2 ~1.3 GB] [video 3 ~1.3 GB] [video 4 ~1.3 GB] [video 5 ~1.3 GB] [video 6 ~1.3 GB]. Each video is on a separate Encore timeline (if this matters). If the screenshot below indicates a good layer break point position, than this is great, as this is the setup and videos I will use for the DVD9 project to be replicated. Below is the screenshot of the ISO file. Is this the layer break point Encore has set, since there is only one? Or is this the only layer break point recommended by IMGburn? _____________________ TEST #2 - 7 videos (5 x 1.3 GB each; 2 x ~ 0.65 GB each) totaling 8.39 GB; only 1 chapter point at the beginning of the timeline. The layer break most likely has been chosen by Encore in the middle of video 4 (see image below of videos in Encore timeline). I deliberately arranged the videos this way to force Encore to place layer break in the middle of a video (which is not ideal), for testing purposes (i.e. to see what layer break point(s) IMGburn shows). As you may see in the screenshot below, three layer breaks are shown by IMGburn. Are these all layer breaks Encore has set (unlikely I suppose), or layer breaks suggestions by IMGburn? Videos arrangement in Encore: [video 1 ~1.3 GB] [video 2 ~1.3 GB] [video 3 ~0.65 GB] [video 4 ~1.3 GB] [video 5 ~1.3 GB] [video 6 ~1.3 GB] [video 7 ~0.65 GB]. Thus middle of 8.39 GB will be half way of video 4. Below is a screenshot of Encore timeline for this test. As you can see, the middle of the 8.39 GB should be approximately half through video 4. Below is the screenshot of the ISO file. I wander which of the three is the layer break point set by Encore, if any. CONCLUSION AND MAIN QUESTIONS Test #1 represents the setup I will use for the DVD9 project I want to replicate. Encore was given good chances to choose the layer break between videos, which is ideal. Test #2 - I do not understand what the three "LBA" represent. Main Questions: How can I know: a. if the layer break in Test #1 is the one set by Encore, or only a suggestion by IMGburn? And, is this between videos or during a video? b. which of the three layer break points in Test #2 is the one set by Encore? Or are they only suggestions, and IMGburn does not know where the layer break point was set by Encore? I apologies for such a long message. Thank you very much for your help. I greatly need it as Encore does not always set the layer break reliably and consistently, and I need to know somehow what it managed to do.