This is done using a military pull the dot snap that when snapped prevents the choil of the knife from coming out of the sheath. Works well on knives with larger choils. Shown on a modular sheath below. Not as secure as a pin-lock.
I make a Japanese style leather saya with a frog that holds the saya. This can be done in different ways depending on the size of the knife.
While I am not personally a huge fan of these, for some smaller knives they work quite well. Makers love them because they require a LOT less leather and a lot less time to make. If you notice my style of knife sheaths, you don't see this style being real common to what I make. I don't sit down and try to figure out what is the fastest easiest sheath to make... I sit down and think about what is the most robust and versatile sheath... what is the best way to make it, not what is the fastest or cheapest. Also, if you happen to fall on this style sheath, there is a good chance you are going to stab yourself as the knife pushes out the end. I already have to worry about breaking a hip if I fall, I don't want to consider getting stabbed at the same time.
Carry that knife on your chest... or shoulder... or whatever. The modular style sheath can attach securely anywhere on the strap.
Traditional Knife sheaths start at $75 for up to 6 inch blades. Every extra inch is $10.
Japanese saya style with frog start at $125 for up to 6 inch blades. $20 extra per inch over 6 inches.
Modular sheaths start at $125 and include the fold over sweat guard/belt loop.
Basic Retention straps and snap locks are $25. Snap locks only work on certain blade styles.
Pin-lock $45
Sweat guard (leather behind the knife handle $20
Ulticlip: $12-$15 depending on clip size.
Ultilink system incorporated into sheath $30
Loki Strap with lined shoulder pad $125
Basic tooling and stamping is free.
Dragon Scales, Basket Weave, and repetitious patterns are $15 for up to 6 inch blades. $5 per inch over 6 and only covers one side of the sheath. See this page for photos.
Thumb-break style with Kydex sandwiched in the leather backing $25
Two-tone color: $20
Exotics: Rattle Snake, American Alligator, stingray, and beaver tail: add $100
Most other exotics add $50
Exotic prices are for up to a 6 inch blade. Longer blades may be extra.
Danglers and straps are $25 each.
Spots .30 each
Belt loops $10 each (this includes the belt loops for the modular sheaths)