Can you pack color with a mag needle and then draw black lines on it with a round liner?

I've seen a design like this and thought whether you'd need to get done with all the black lines and then switch to red and color the gaps or would you just lay down the color inside the design and then do the black lines on top of the red without the concern of red goin over the finer parts of the lines.

I would really appreciate some info on how the layering would work on a simple piece like this.
In summary, do we fill in the gaps, or do we draw on top of the color?

If I have understood your question, I would advise you to put all of your black in BEFORE your red, assuming it will all be completed in one session.

Why?

If you apply a colour and open up the skin as you pack it in, you’re likely to muddy (dirty) this colour when you start using black again. This rule applies to ‘tones’ or values, rather than colours. This is why (in most cases) we apply all of the darker tones before lighter ones.

I had the privilege of watching a well-known colour realist artist in our studio this week, and he completed a colour portrait working (essentially) from the bottom of the design to the top BUT was super careful about always wiping away from open skin.

In most cases we work dark to light across the entire design.

Seigard said:

I've seen a design like this

https://imgur.com/1eQM2qf

and thought whether you'd need to get done with all the black lines and then switch to red and color the gaps or would you just lay down the color inside the design and then do the black lines on top of the red without the concern of red goin over the finer parts of the lines.

I would really appreciate some info on how the layering would work on a simple piece like this.
In summary, do we fill in the gaps, or do we draw on top of the color?

Click to expand...

You have to build confidence in your lining and packing.
Try to get more precise, as melting colors just changes them: that's the main risk.
As Whippet said, a lighter tone will not modify (or just a little bit) a darker one. The melting is always there, but better keep it on the width of an hair than a millimeter!
Even when we do gradients, we always start with the darker tones (black if used), because it's our darker dark as some would say.
You can only go darker, never lighter, it's colour theory basics in tattooing.
So if you have from the start your darker tone reference (by black lining usually), you can cautiously build your lighter ones.

Hope this makes sense.

Peace,

DKJ