Interfacing holds up hem.  This is a great way to create an invisible hem.  Do not use on transparent fabric.

There will come a time when it would be preferable to have stitching of any type showing.  This means creating an invisible hem line.  Even when great care if taken, stitching can show through to the other side.  Particularly on fabrics like silk and satin..  This technique can be used for gowns, jacket hems or a lined sleeve.

Hold up hem with interfacing

This little trick is great.  Measure out the length of interfacing you will need.  This will be the length of the hem.   Measure the hem allowance.  Double this amount and this will be the height of the interfacing.  Fold right sides together (non sticky) and sew across the raw edge, or a little lower.  Try different positions until you like the result.  Now iron the interfacing in between the hem allowance.  The hem allowance will not fall down, because the stitching in the middle of the interfacing is holding it up.

The only comment I have with this is to ensure you use a good quality interfacing that will iron on and stay ironed on.

TIP - DO NOT USE STEAM WHEN IRONING ON INTERFACING.  The interfacing may stick initially, but when steam is used it can fall off later

Happy altering
Judith Turner