One of the main reason the sewing machine dominates the production of leather briefcases and all garment manufacturing is that almost any factory worker can easily be taught to use the machine. Stitching by hand and making it look pleasing is an art-form, especially with one of the most complicated leather items to produce – a briefcase.
This is a lost art-form with no advanced classes taught in American fashion schools anymore. The few craftsman that attempt to hand stitch might not have the master level needed to produce a strong lasting stitch. It might look good on the outside but hidden between the stitching layers might have future issues.
With each hand stitch, leather sewing needles enter the hole and it is at this point where skill is needed not to puncture the thread, something a machine does NOT do and why it is better in this regard. Look at it this way, unskilled hand stitching is worse to the bond than unskilled machine stitching.
Hand stitching is stitched “in the air,” meaning I am not pushing a needle and thread against a metal plate. The sewing takes place literally in my hands, allowing me to get shapes and corners out of a briefcase a machine can not do. Hand stitching also tends to have slightly bigger holes because they are punched by hand and sewn with hand needles. The hand is limited to how small it can get, especially with thick bridle saddlery leather.
An Important Aspect Of Hand Stitching Is how clean the stitch is on BOTH sides.
As Far As Strength
A hand saddle stitch, the stitch that holds horse tack together for a 2000 pound animal, is a stronger bond than a small sewing machine stitch.