I am often asked about zips. If you've been sewing for a while you will probably know the basics but for all newbie sewers here's a brief guide
zip types - zips are either open or closed end(ed). Closed end zips are probably the most commonly used. They are called closed end because when you unzip them the two halves stay joined at the bottom. They are sewn into a seam, in a dress, skirt, trousers, cushion, bag....I could go on. Open end(ed) zips come into two separate halves when unzipped. These are used for openings in a jacket, or cardigan. If you used a closed end zip in a jacket you would have to climb in and out of it! There is a special type of closed end zip known as a concealed (invisible) zip, so called because you can hardly see them once sewn in. These take a bit of practise (and a special foot for your machine) to sew but give a lovely neat finish.
length - the length of a zip is the length of the part with the teeth. There will be an extra 1-2cm (3/4 inch) or so of fabric at the top and bottom. Most zips are from 4" (10cm) up to 22" (55cm) but you can find longer and shorter ones if you need them
weight - zips may be sold as "lightweight", "heavyweight" etc or by number...the smaller the number, the lighter the zip. So a number 3 zip would be medium weight, general purpose and a number 5 would be a bit thicker and heavier. In most cases you choose the zip according to the fabric you are sewing it into. Number 3 would be suitable for most dressmaking and for medium-weight cotton cushions and furnishings. If you were making a thick coat or sewing a canvas bag or cushions for a sofa, you would need a heavier zip and delicate lingerie would need a lightweight zip. Most modern zips are made of nylon or polyester. Some of the heavier zips will be chunky plastic or metal.
colour - whilst the length and weight are important considerations to get a good finish the choice of colour really is personal. Most people would choose a colour which closely matches the fabric (or the background colour of the fabric if it's printed). If you prefer though, you can pick out one of the colours in the design or even a total contrast. This is what makes your creations unique and the zip can become a real feature so please experiment
- Sharon Rogers