As the title states, I am looking to replace my Retzuos on my Tefillin.
I would like to know if this is something I can do on my own, or should I seek a Sofer? Are there any resources online if I were to replace them myself?
Also, what is the halachic difference between the black on white straps and the black on black straps?
Some twenty year ago or so, I went to one local sofer and he offered me a choice of machine processed or hand processed. I asked which is better, and he said the machine processed. I chose the latter . Those retzuos are still good, buttery soft and with some longitudinal creases that show it came from a cow. This was before the advent of black on black. I recent ly replaced retzzuos on a different pair. The black on black smells toxic, feels and looks like plastic with hard edges, and shows no sign of breaking in. And yes, go to a reputable sofer