As far as supplies go, Safran seems pretty straightforward at first: you’ll just need iron-on interfacing, a zipper, and a button. There are however a few subtleties: the interfacing needs to have some stretch, and the zipper has to be sturdy enough to sustain the tension of the fabric. Here are our tips to pick the right notions 🙂
Safran’s waistband pieces are interfaced, which means that they are reinforced with an extra layer of special fabric (the interfacing) which consolidates the fashion fabric around the buttonhole and prevents the waistband from creasing with wear. It is particularly important to maintain the fabric’s stretch in order for the pants to be comfortable, therefore the interfacing needs to stretch with it. There exists two types of stretch interfacing: knit interfacing and bi-stretch woven interfacing. Good stretch interfacing should also recover its initial size after being stretched out.
In North America, Pellon interfacing reigns supreme. EK130 “Easy Knit” is a knit interfacing that can also be used on stretch wovens, and 865F “Bi-Stretch Lite” is a bi-stretch woven interfacing suitable for lightweight fabrics. You can find these at Harts Fabric, Stonemountain & Daughter, or Fabric.com.
In Europe, the most common brand is Vlieseline. Two of their references can be used for Safran: G770 for medium and heavy-weight fabric, or G785 for lighter fabric. You can order it online on Tissus.net (in black, white and nude), Rascol or Ma Petite Mercerie.
However you don’t need brand-name interfacing to make a good pair of pants! If you can find off-brand stretch interfacing in your local store, it will work just as well.
Stretch fusible interfacing works exactly like regular fusible interfacing. Because of its elasticity, it is even more important to make sure not to stretch the interfacing with the iron when applying it, or interfacing bubbles might appear after the first wash. Be very careful to lift the iron and put it down vertically instead of sliding it on the fabric!
For Safran’s fly front, you will need a non-separable metal zipper, as the zipper should be sturdy enough to sustain the fabric’s tension. Stay away from plastic zippers, even the ones sold as “pants zippers”. Metal zippers with teeth 3mm (#3) to 5mm (#5) wide will do the trick. A #5 is preferable if you are sewing the jeans version, or if your fabric is on the thicker or less stretchy side.
Be careful to buy the correct length as well! A zipper is measured from the top to the bottom of the teeth (the length of the tape itself doesn’t count). For Safran, you’ll need a 6″ or 15cm zipper. If you are using the metric system and cannot find a 15cm zipper, you can also pick a 14cm one and move the end-of-zipper mark up by 1cm.
To close the waistband, you have the choice between a sew-on button or a jeans button, depending of what look you want to achieve. Jeans button are hammered in, after forming a hole in the waistband in which you insert the rivet. You’ll find a wide variety of designs, from the most sober to the classic laurel wreath. If you are feeling hammer-shy, you can make the task easier for you by using a jeans button kit with the corresponding plastic tool.