Well bud,I'll tell you something.It all depends on which process.Here goes!

Most Important to wear leather is in SMAW processes!

Medium Important is to wear lighter leather is Mig Welding along with flux core!

Tig welding can be done in a sunday church uniform and that's why I love it because gas welding gives my garage a break!

Yes,many companies supply leather such as the J TILLMAN company!...Look on the web or go to airgas safety and get an account and get lotta safety supplies.

You are so welcome bud!

GLD,
What position was your welder welding in? Sounds like possibly he/she was welding overhead or possibly another position that was higher than his head and had a shower of sparks/slag falling across his/her back. Leather seems to be the material that most welders clad themselves with to keep from catching fire. Green capes and sleeves work if the welder is occasionally under these conditions, but leather works best. These articles of clothing are available from your welding supply shop. Keep away from clothing made from synthetics, such as polyester and the like. I have welders that like to sit on a bucket and weld/or cut. This is not a good practice either as it gives the slag/splatter a place to land and collect in the lap. A piece of leather added to the bottom edge of the welding shield does two things, first it helps keep from getting a flash burn on the neck from the radiation, secondly deflects splatter/slag from entering around the neck of your shirt. Some of our welders use only leathers and some add another layer of the green clothing underneath, that is fire retardant. Use what ever measures are appropriate for your conditions. Welders will get very hot and can overheat under all this protection in the summer heat, so give them an extra water break when temperatures rise.
John Wright

GLD

I have a number of clients in the oil & gas industry. A number of years ago Conoco introduced a mandatory clothing requirement for all workers around “hot work” (welding, cutting, tapping etc.) to wear Nomex coveralls or shirts and bibs. DuPont owned Conoco and they had developed this fabric for firefighters, race car drivers and the like. There are now numerous manufacturers of this type of fire resistant work clothing. It is now standard attire in most refineries, gas plants, drilling rigs and so forth. Even Carhartt has a line of this clothing. Welders do complain that the material does break down over time after exposure to sparks, especially grinding sparks. The material is also a little on the lightweight side. The tight knit of the material does not allow much air flow and it can be uncomfortable in the summertime.

Most companies supply this clothing, they treat it like the expense of hardhats and steel toes......cheaper than loss of use or life. They most likely get a break on insurance costs as well.