What is this wood figuring called?

[HoGo]

Since posting this I have been reading a bit about it elsewhere.
Apparently engelmann spruce has particularly long medullary rays, which are what makes this pattern figuring.
They show up in guitar tops when the cut is just right, but I guess mandolin tops start out thick, so as you carve down you are more likely to hit them.
It is really interesting stuff.

They are everywhere in the spruce wood, but they are best visible when you cut exactly along them (e.g. radial direction from core of tree towards bark) few degrees off and you see nothing. On guitars they either show on large surface (meaning the part is perfectly quartersawn) or don't. If the wood has some runout the rays will be thin lines if the wood is both perfectly quartered and no runout then they will create fatter patterns and kind of tiny curl like in pics of the guitars above. You can see all these changes in mandolin tops as they are not straight but curved. So unless your mandolin has wood very badly cut you'll see them somewhere.

[Jesse Kinman]

Here’s some pictures of my Tyler White, which is Engelmann, followed by my Kentucky KM900, which they say is German Spruce, followed by my Huss and Dalton, which is Sitka Spruce.

[Jesse Kinman]

My Tyler White has a hand rubbed finish tho, and the Kentucky is sprayed, that might be the difference in why the White has that particular coloring like your Northfield

[dang]

Is that what’s on the top of my Northfield Octave Mandolin?
Seems to be a theme with Northfield

[CWRoyds]

Is that what’s on the top of my Northfield Octave Mandolin?
Seems to be a theme with Northfield

Yup, looks like it.
I saw a Northfield Octave recently that had a ton of Silking on the top.
It was a beautiful instrument.
Sounded amazing too.

[pheffernan]

Is that what’s on the top of my Northfield Octave Mandolin?
Seems to be a theme with Northfield

That theme might tell us something about the attention to detail that Adrian and crew are paying to the quality of the wood they are sourcing (and pretty much every other aspect of production).