Then select one of the two layers of stacked rings, and add as many as possible rings to both chains, in this selected layer. The example uses yellow rings to show that. Note that 'higher' HP chains may need more than two rings in that step.
While this tutorial shows only joining of two Half Persian 3in1 segments, the method works for ALL Half Persian chain weaves - the taught method needs just to be applied analogous for these.
Let's start. First, arrange both to be joined chain segments in a way, that their ring layering, followup pattern, and finally orientation is identical.
Then select one of the two layers of stacked rings, and add as many as possible rings to both chains, in this selected layer. The example uses yellow rings to show that. Note that 'higher' HP chains may need more than two rings in that step.
Now layer the two chain segments upon each other in a way, that the layering pattern of the just lengthened ring layer is continuous. It is possible, to use a piece of wire as 'guide', to maintain the layering pattern - similar to the 'on-a-wire' HP starting method shown elsewhere in my tutorials. This is optional (and sometimes impossible if the weave is tight), and may help a beginner, but will surely soon prove unnecessary, anyway.
Now it's time to fill the gap of the other ring layer, to make finally the join. This is shown with red rings - as you see in the photo, just continue that ring layer's weaving pattern.
After adding a second connector ring, in the same manner, the join of two HP3 segments is already finished.
As alread hinted at, the shown method works also for 'higher' HP chains, like e.g. HP4in1, HP5in1, or whatever. Just the number of needed 'red' rings will rise, to three, or more, like the number of 'yellow' rings rose in the second step...
Have fun.
-ZiLi-