Transparent white???


Dart Vader

I posted my experiment in "Works In Progress & Finished Artworks" so that I may benefit from the critiques of forum members. I did receive excellent replies.
First attempted experiment in Biomech

One such reply was from Squishy:
...This is looking great, my only criticism is that I feel the white highlights look like white lines painted on, and I think would look more natural with a more gradually built up fade, although I appreciate there's not much room to work with...

I completely agree with Squishy"s observation. So the following questions popped into my normally dormant mind...
Would the use of a transparent white enable me to create a more "wet" look to the design?
Can a transparent white be achieved through adding more reducer than standard detail painting?
Or, if neither of those are the "better" answer, then is there a specific method to achieve that "wet" highlight appearance without making it look like painted on white lines?

I do realize that there are no hard/fast "rules" regarding types of colors and the methods in which they are used, but all suggestions will definitely be considered and greatly appreciated.
Thank you to everyone who replies.