Pop song title.
Anyway, I'm choosing the Donihoo style holster that appeared circa 1960 and was made by most every company of the time, to illustrate the big difference between thinking a designer is applying a craft, or a science, to creating then building a new design for his line.
I'll show a series of them, then I'll make my point (and I do have one):
A Ball above, a Becknell below.
A Bianchi above, a Bluemel below.
A Cobb above, a Lawrence below.
A Myres above, a Polk (not really) below.
Above and below are both Safarilands; but now I'm going to give you a hint: look a the stitching of the main seams between the two.
Above and below both are Seventrees; but the upper one is by Ken Null while he built gunleather for Theodore and the lower one is a prototype of the Seventrees.
Shoemaker above, Trammel below.
Voigt above, a Brauer below; the only closed muzzle versions so not really 'Donihoos'.
And a Wolfram below, the first of the Donihoos to appear (circa 1960):
Now, Donihoo hung out with all these makers and convinced them to add the design to their ranges. He is pictured in an early Bianchi catalogue, and Bianchi was closely associated with Wolfram (above), and Wolfram's is the earliest known of the Donihoo style. Then we have records of Donihoo attempting to justify the design to the Seventrees people and esp. wanting them to use the same horsehide that Gaylord was using (all came from the same place, though, only one American tanner of horsehide then and now; I agree that horsehide is the ultimate material for the Donihoo Speed Scabbard.
Above, Donihoo and his scabbard in an early Bianchi catalogue.
Okay. Holstory (the field of study vs the book), tells us that the Donihoo was created as a 'speed scabbard' for autos to be equivalent to the Threepersons for revolvers: TRUE THREEPERSONS FOR REVOLVERS WERE STRAPLESS. And this was accomplished by making the holster tight and sewing in one or more thick welts to squeeze against the revolver frame (the SA has a long tapered frame but the DA only a very short, smooth frame ahead of the trigger guard, so doesn't work well).
But as I've written before, the purpose of welts was 'forgotten' over time and all those holsters had straps added to their standard configuration. Below, before and after Bianchi 'Threepersons' of the 1960s, same holster which is a direct copy of the Heiser 459:
The wrong part of the retention-without-a-strap was learned from the revolver. AND IT DOES NOT WORK WITH THE 1911: almost literally impossible to remove the pistol from the completed holster with thick welts rubbing against the dust cover of the auto. Nope, a Donihoo used DIFFERENT principle: a pair of widely spaced stitch rows that CLAMPED THE SIDEWALLS of the holster. Very pronounced in horsehide which is very stiff.
So look again at the first set of images.
Most have only one row of sewing. HONK! Fail. And to those the makers added a strap.
Some have the thick welts and the widely spaced twin rows of sewing. But HONK! Fail, the welts rub hard against the frame.
Then Goldilocks: twin rows widely space but well away from the pistol. Which then slides out against the compression by the sidewalls but without the interference from the welts.
THE STRAPS WERE ADDED BECAUSE THE DESIGNER/MAKERS DIDN'T UNDERSTAND THE SCIENCE BEHIND THE DONIHOO, AND THOUGHT IT WAS THE SAME AS THE THREEPERSONS. They were wrong. What the science of gunleather allows us to do is PREDICT what will happen, so that a poor design doesn't get out into the field. Such as the Safariland Kydex holsters for light-bearing pistols that left a gap at the trigger where small items such as keys and fingers slipped in. BANG! But if they'd really been pros, they wouldn't have convinced themselves the HAD to leave the gap to get the mounted light into the holster.
Right up there with following too closely in the rain on a motorcycle at 100kph: "I had to, because it was raining and there was so much TRAFFIC". Nope, false logic. It's not I who say one can't stop in time, it's science!
Now my Donihoo, below in horsehide, as Berns-Martin Australia. Guaranteed to fit and retain without a strap, right out of the box, for the working life of the maker (but I'm retired so . . .). Notice the relationship of the stitching rows to each other, and to the pistol; inside is a thick welt, too:
Read more in my book titled "Holstory -- Gunleather of the Twentieth Century -- the Second Edition" that is available at www.holstory.com and printed for you/shipped to you in USA.