Robert Steibel has posted on his site a Jack Kirby Captain Victory drawing that was allegedly inked by Jack's wonderful wife Roz. It really wasn't inked by her. At best, it was co-inked by her. Allow me to explain…
Jack largely lost interest in a story after he had drawn it in pencil. The "storytelling" part of the job, which was mainly what he cared about, was over and his mind was on to the next story. So to go back and ink that first story was not a major concern for him and sometimes an intrusion. He did it on a lot of his pre-1960 work, usually because no other work was available. Or to put it in simpler terms: In the time it took him to pencil and ink one story, he could instead pencil two. Penciling two was more fun for him and it paid better. If he couldn't get that second assignment right away, he'd want to ink the first job and make that money.
But he still didn't like inking. So what he'd do was to have Roz take a pen — usually one with a fairly inflexible tip so it put down a very static line that didn't get thinner or thicker — and she'd trace his pencil lines. Roz had a little experience in fashion illustration, mostly doing ink linework on drawings by others. That's what she was doing when they started dating.
Once her work on his pages was done and the ink had dried, they'd erase the pencil and then Jack would go at it. He'd take a brush and he'd put in the bold lines and the large black areas and the shadows and everything on the page that was thicker than Roz's static pen line. She might wield a brush but mainly to fill in black areas that Jack had already outlined in ink. I would say that in most cases, the ink on the published work would be 90% Jack's…but Jack would still tell people that Roz had inked it.
Why? Well, he loved her and he didn't need the credit. Truth to tell, it was only later in his career — after I met him in '69 — that Jack cared much about who inked his work. He had preferences but he accepted almost anyone.
Late in Jack's career, there were a few times when Roz "inked" pieces on which Jack did little or no re-inking. She even tried inking for real with a brush…but no one would mistake the results for the output of a professional inker. These cases were a few commissions and a few drawings for convention program books…but mainly I'm thinking of presentation art he did for animation projects. As Jack's vision and muscle-control grew worse during the eighties, it affected his ability to ink more than his ability to pencil. You can get by as a pencil artist if you have a slight shake and an unsteady hand. It's more of a problem when working in ink or trying to maintain the delicate touch necessary to make a brush do exactly what you want. He had good days and bad days…and on the bad days might leave more of it to his spouse. But that Captain Victory piece was mainly inked by Jack. I'd say at least 80% of it.
P.S. Added Later: I missed the fact that Roz's signature on the piece was dated 1997, which was three years after Jack died. Roz died in late '97. I believe this piece was a commission that Jack started, possibly over a tracing of an earlier drawing he did, and which Roz finished after his death when she had a buyer. Looking closer at the foot at lower left, that's her trying to finish the inking, following the style on the rest of the page. So I'll revise my estimate down to 70% Jack. My point is that this is not pure Roz Kirby inking. She was a wonderful lady and she was not without some artistic talent…but she was not capable of inking this good on her own.