The Jean Genie is my invention for altering a jeans hem
One of the biggest problems people have shortening jeans is sewing over the thick side seams with their domestic sewing machine.
There are some products on the market which will help you do this, however what the Jean Genie also does is make sure you cut the correct length. I can't tell you how many times I had people come in and say that they had shortened their jeans or someone else had and they were too short. Jeans usually cost a reasonable amount of money, so cutting them too short can mean the jeans are ruined. Usually the person folds the jeans up at the right length and tries on their shoes, but when it comes time to cutting, they cut on the fold line. That means no hem allowance. The Jean Genie has slots for you to mark with your tailors chalk. This ensures you cut on the bottom line and have still got your hem allowance.