Hi Shooey,

let's just make sure we are talking about the same thing.  When you say feather are you describing "a Holdfast" which is created when you carve out a trench on either side near the edge of the insole? I have heard a holdfast being discribed as feather because it is close to the edge of the insole which is usually tapered, but i think this confuses and generalises things.  If you imagine a feather you see it comes to a fine edge just like the insole when it reaches the edge. Featherline is the edge on the last the you bring the insole to a feather at when you shape the mounted insole.  So the holdfast is just inward to the feather. I know terminology will be different across the world , but what I have written is direct from the etymology of the words. Example "holdfast" is really where the welt and upper are "held" securely to the insole.

In any regards a hand welted shoe can have dimples regardless if there is a tapered edge or a holdfast. Not having either is more typicial with a chunkier shoe or a Norvegese construction for example where you don't need to taper edges and the storm welt allows you to stitch in almost a straight line. You don't need to dig a trench thus no holdfast. The trench = holdfast is necessary when you want the stitches to exit the same plane you enterred. it allows to make your stitch deeper all the while keeping things very tidy. A really elegant svelt shoe with a blind welt and a nice tight waist will typically have a well pronounced defined "holdfast" and feathered edges. Basically I want the welt to be stitched at the bottom of the shoe not on the sides like chunkier shoes.
Basically the dimples just represent a tension that is applied perpendicular to the surface of the insole in all handwelted shoes. The dimples often become more pronounced as the leather dries out or if the stitching was done initially very tightly. Keep in mind that it alos depends on who is closing the shoe and how deep the stitching went. Personally I like to have as much material between the stitch for strength and this means going very close to the surface you see and thus more visible dimples. Machine made shoes don't have dimples because there is no direct connection of the stitching to the inner sole because of the presence of gemming ect. there is no proper transfer of tension. In the case of Blake for instance the dimples are replaced by the visible thread.

Does this all make sense shooey?

for the santoni norvegese, ONLY the pairs with the additional stitch thru the side (in addition to the downstitch that goes into the topsole) have the dimples.  I am seeing the dimples in their bentivegna pairs as well.  I believe that the stitch thru the side attaches to the feather of the insole, thus causing the dimpling (since it is pulling to the side, rather than straight down (as in regular handwelt).