oK, I use the old English style which is a spring loaded tool.
And the reason l still prefer it is this.
I can place very accurate whips and also alter thread tension during the process.
Frank Marterelli then changed this to a rotating system, there after we saw the cheaper Asian versions from India, Pakistan, and China where most tools are made to day. Unless they are high end products.
The imported versions of the old English style are no use as the arms are bent in the wrong direction and do not allow easy thread control.
I will post a pic of the one l use, and have done for over 45 years.
Varnish.
Ok if l want high gloss heads for show flies than l would so this with lamination's of a very costly nail vanish called Super Shiny, its about $20 bucks a pop.
For my regular fishing flies l use hard as nails. Nail varnish is not as good if you use thinners such as acetone.
Cellire varnish is also good.
Matter of interest here, l always use two whips to my flies.
First is 2 whips and finish and then 3 and finish, its been a habit since my early days tying with silk threads.
Davy