I'm weaving black tencel yarn at 24 epi in a 12's reed at 2 ends per dent. I have a floating selvedge at each side, just using 2 threads in a dent rather than "doubling up" to 4 selvedge threads in the end dents. With these relatively fine threads and my failing eyesight, I find it difficult to pick out the selvedge threads. Are there any methods by which the selvedge threads can be made to stand out from the other threads. The loom is a Lillstina 4 shaft counterbalance.
You could add a strand of a smooth, brightly colored yarn with a free weight to the heddles. When you are done, gently pull it out. The extra space from the thread will disappear in the washing.