I use shellac less and less, but mainly because my handlebar choices have moved more upright (with grips) over time.
But, I do like using flake shellac, since you can choose to dissolve only a small amount (in alcohol) of flakes, enough for a handlebar or two and you don't need to have a gallon of shellac sitting around your house.
You can get flake shellac in a lot of different stores that sell woodworking material, or online, I suppose.
cheers,
John