One other reference I forgot, you might recognize the source 
;
How to toughen up your fingers https://www.guitartricks.com/blog/How-to-Toughen-Up-Your-Fingertips
"It takes a lot of devotion and work, or maybe I should say play, because if you love it, that's what it amounts to. I haven't found any shortcuts, and I've been looking for a long time."
-- Chet Atkins
-- Chet Atkins
