I want to thank Colleen Doran for allowing me to share this! (Be sure to follow Colleen Doran on Twitter!)
Colleen shared:
Thanks to artist Guy Dorian. Marvel returned my art from “Captain America and the New Warriors” to him by mistake in the 1990’s. Guy found it in a stack of art in his attic and returned it to me this week! Thanks, Guy! You’re a swell guy! Wonderful inks by Greg Adams, btw!
This is pre-digital color. What you are seeing is an old fashioned printing instruction. The red line tells the color separator that the line is to be a color hold, a line of color printed without black and white ink. This work isn’t done anymore in this way.
Original posting of image:
https://twitter.com/ColleenDoran/status/1407358625413275650?s=20
And:
https://twitter.com/ColleenDoran/status/1407358625413275650?s=20
Thank you Colleen for sharing! <3