Many gun writers & tactics instructors advise using a system for a concealed firearm; belt, holster, spare mags, light-OC spray holder etc. the items should fit snug & not slide all around.
Most good belts should run about 1.5" wide. A few clever designs like Mitch Rosen or KL Null narrow the dress belt to 1.25" in front to aid concealment.
Top brands for well made gun leather or synthetic belts include;
www.usgalco.com www.thebeltman.net www.blackhawk.cim www.galls.com www.policehq.com www.5.11tactical.com www.miltsparks.com www.mitchrosen.com www.donhume.com www.safariland.com www.kirkpatrickleather.com www.tedblockerholsters.com www.highnoonholsters.com . Leather type materials or lined belts are high quality. Greg Kramer; Kramer Leather sells horsehide & other exotics.
Del Fatti does too.