To make sure you join the right piece to the right piece you need a clue as to which pieces go together. You may also need to know which is the front of a garment and which is the back -this may seem obvious, but when they are all flat it isn't!!
N.B. With some fabrics it is also helpful to mark which is the right side (from now on known as RS) and which is the wrong side (from now on known as WS), but we'll talk about that later!
NotchesThese are the diamonds on the cutting line and they are either single or double. When cutting out, you are supposed to cut out and around them. It seems like a real faff, but it is well worth it later and can make sure you don't make a mistake when you are making up. One notch means the front and two notches together means the back. Occasionally you have three notches together too!
Tailor tack dotsThese are little filled in dots or open dots. They may seem pointless but again they show important marks for you to sew up to so you must transfer them on to your fabric, I'll show you how at a later date.
Grain line arrowsThese are the thick black lines with arrow heads on each end, sometimes curved ends. All fabric is made on a machine and has a 'grain.' If the grain is straight the fabric hangs straight, across the grain gives a stretch that can be useful at times but also can ruin the way a garment hangs, so it's important to understand about grain before you cut out.
Grain Woven fabrics are made on a loom. The threads running down the loom are called "Warp" threads and the threads woven in and out going across the loom on a shuttle, are called "Weft." Warp threads are stronger, so we always line our pattern pieces up with the warp threads. How?? Well it's easy, when you buy fabric on the roll the two side edges are neat and they do not 'fray', that means threads do not come off them. These two side edges are called "selvedges." All threads parallel to these selvedges are the warp threads. If your grain arrows are parallel to the selvedges then you are fine! Here's how to do it!
Place your pattern piece on the fabric, weight it down with something like your pin cushion or your scissors. (More about folding and pinning on fabric tomorrow)
Grab a tape measure or a ruler and measure from the grainline to the selvedge at each end of the line near the arrow heads and make sure the measurements are identical before you place a pin in each end of the grainline. Simple! Sometimes needs some jiggling to get the piece straight, but it is important and near enough is not good enough!! It needs to be exactly the same measurement at each end! As you can see I still work in inches but you use metric if you are happy with it!!!