Ian, here is a link to another loop thread on this website with a video of how to make your own chinese squeeze knotless loops.
Loop the Loop - which loop and why?
It will bring you to the post with a video link at the bottom of the post showing how to make them. Few people fishing the salt use the bought ones because they are too short and are sometimes not made properly.
You can use that identical technique with the braided mono loop to make a knotless loop in backing such as Cortland Micro, any trolling braid, or hollow spectra.
Here is a link to a better (I think) way to actually connect a backing loop to either a factory welded running line loop or one made by you. It is illustrated with three pictures. The second one clearly shows how the connection should look prior to clinching it up.
Loop to Loop connection
The third photo shows how, after cinching up the connection, the connection stays very small even without tension on it. It will glide through the guides much better than a standard connection - especially noticeable when used on a welded loop running line. It also will never flop over and wind up in a position to cut through the fly line loop.
When making a loop, you can size the loop after turning it inside out and the tag end will remain the same length. If the tag end changes length when resizing the loop, you started from the wrong end, and the loop will, sooner or later, fall apart - often just casting with it.