Straight-leg jeans are the classic silhouette. The widest part of the jean is at the thigh and the jeans retain that same width through to the knees and calves and down to the hem of the leg opening. Skinny jeans are form fitting from the waist down to the ankle. Most skinny jeans are made from denim fabric that contains a small amount of spandex. This allows you to fit your heel through the leg opening. If you have a closet that is full of straight-leg jeans and want to make some look like skinny jeans, there are steps to follow.
Put your jeans on inside out and sit down on the floor with your legs pointing straight out. Center your leg in the jean's leg
Focus on the seams. Most jeans have four seams, one on the outside of each leg (side seams) and one on the inside of each leg (inseams). Mark with tailor's chalk where each seam naturally stops touching your leg. This will be the starting point mark.
Hold tight to the seam with one hand and gently move your fingers back and forth until they almost touch your leg.
Attach a safety pin, parallel to your leg, through the front and back jean fabric at the spot where your fingers are holding the fabric close to your leg.
Continue this process all the way down the side seam to the hem. Place the safety pins about an inch apart. Repeat this process for the inside seam of your left leg.
Remove the jeans. You may have to move the safety pins further out to allow for a wider leg opening.
Place the jeans (still inside out) front side up on a hard, flat surface. Draw a line next to the safety pins with your tailor's chalk, starting at the start point mark, moving down to the hem of the trousers. Use a ruler to straighten the line. Do this for both the side seam and inseam. This is your sewing line.
Draw a second line 5/8 inch out from the original chalk lines on both the side and inseam. This is your cutting line.
Fold your jeans in half, front sides together. Lay the folded jeans on a flat surface. Apply pressure to the leg of the jeans with the heel of your hand. Rub up and down the folded jean legs. Be careful not to let the legs shift.
Unfold the jeans so the front sides are facing up. The chalk from the left leg should mirror the mark on the right leg.
Begin at the hem and cut along the cutting lines for the side and inseams. Stop about an inch from the start point mark. Use the seam ripper to take apart the last inch of original seam stitching. Place a straight pin at the start point marks.
Sew a zigzag stitch along the raw (cut) edges of the jeans. This will keep the new seams from fraying when laundered.
Pin the right sides of the front and back left leg together along the side seam sewing line.
Sew in a straight stitch along the sewing line. Begin about 1 inch back from the start point so the first stitches you make will overlap the original stitches. Remember to back stitch once you reach the hem. Repeat this process for the other leg.
Iron the right and left side seams open. Look at the original seam stitching for the side seams. Most denim jeans have double welt seams--two rows of top-stitching--usually in a contrasting thread colour to the denim that runs next to the seam.
Trim the seam edge closest to the back of the jeans down to 1/4 inch. Iron the remaining seam edge over so it covers the 1/4-inch seam edge. Turn the trousers right side out.
Measure the original seam and draw new topstitching lines to match the originals.
Begin sewing each topstitching line so it overlaps the original topstitching line by 1 inch. Back-stitch at the hem.
Turn your jeans wrong side out. Pin and then sew along the inseam sewing line for both the right and left leg. Back-stitch at the hem.
Open the seams and iron flat. Cut any loose threads.
Look at the original seam stitching for your inseam. Some jeans don't have any topstitching on the inseam. If your jeans had topstitching here, use a seam ripper to remove the remaining topstitching. It is difficult to add topstitching to an inseam on skinny jeans with a home sewing machine.