You are teaching your friend how to lay out pattern pieces so that they are "on grain." Write, in detail, what you would tell them. What would happen if you did not lay your pieces out on the straight-of-grain?

In order to have a perfect-fitting garment such as pants, a shirt, or even a dress, the pattern pieces must be layed out on the fabric so that they are "on grain." By this, I mean that the fabric must be layed out evenly on the threads of the fabric that are woven in the same direction. On each pattern piece, there is a line with an arrow on each side. This is called the grain-line arrow. On a pattern piece, the grain-line arrow helps you to be able to tell if the pattern in "on grain." In order to be able to tell, get out a measuring tape. Measure one side of the arrow to the selvage and then pin the pattern piece down into the fabric. Next, measure the other side of the arrow. Make sure that this side is the exact same measurement from the selvage edge, then pin it. Once both pins are in place, the pattern in considered "on grain." This helps with the finished product and making sure the garment will fit correctly to the body and it's curves. Otherwise, some parts of the item may be tighter or looser than the other parts. This would be the result of an error in the measurements for the grain-line arrow. To have a perfect, well-fitted garment, the grain-line arrow must be measured equally from one of the sides of the fabric, preferably the selvage, and must be pinned down to eliminate the chances of messing up the measurements.