My modernized Sgian Dubh started with a conversation with a customer and good friend. He was asking for a knife to wear on deployment, and had always liked the history of the Sgian Dubh.
The Sgian Dubh - black knife - is of uncertain origin. You can find all sorts of historical claims about it, many conflicting. We can say a few things with fair certainty: It's been around a long time. It has been variously worn as an armpit and sleeve knife, a sheath knife, and a sock/boot knife. Its name seems to come from the idea that it was at one time a hidden hold out- a purely self defense blade.
Through the last several cycles of Scots and Celtic Revivals, the Sgian Dubh has changed. Currently, you are less likely to find a decent mid-range blade, as you are more likely to find a very small, plastic hilted piece of chrome plated pot iron, low grade stainless, or even plated brass, with a plastic jewel on the butt. There are plenty of custom makers and decent shops producing good quality sgian dubhs, but it isn't by any means the rule.
I developed a design for a basic blade that's a traingular profile- a modified spearpoint- with little belly, a fairly thick spine for the type of knife, and a 3.75 to 4.75 inch blade. I dislike thin handles scales on principle, and had to spend some time finding a pattern I liked to make the handle comfortable for use and still low profile. Our Sgian Dubh comes with two sheaths, a short sock sheath as well as a belt carry sheath.