So, let's start by looking at cutting fabric. Although this series is more about calculations, accurate cutting is paramount to making accurate sized quilt blocks, so it is the perfect place to start. There are lots of different methods people use for cutting, and mine isn't the 'right' way but it works for me, so I'll talk you through how I approach it. For the purposes of this post, I will demonstrate how I would cut 5 1/2" squares from yardage.
Dear Leanne and Jess, What is the most accurate way to cut my fabric – using my cutting mat, or my rulers?
Personally, I don't use the grid on my mat at all when I'm cutting fabric - I only look at the grid on my rulers. Cutting mats are more susceptible to warping (ie bending) than rulers, and a warped cutting mat will not give you an accurate result. Rulers are also susceptible to bending, but since they are much harder plastic, they won't warp as easily. If you are careful with how you store both tools (ruler and mat) it shouldn't be a problem; mats should be stored in a cool area away from direct sunlight (don't ask me how I learnt this!) and kept completely flat. Rulers are best stored in the same conditions - I hang my rulers from a long peg that is driven into my sewing space wall, but in the past have stored them flat on a desk.
If you will be using more than one ruler when cutting fabric for a project, it is a good idea to use the same brand of ruler for all your cutting, as there may be minor differences between different brands of ruler. I have a LOT of rulers, and I like them each for different tasks. These are my two 24" long rulers; the Omnigrid is 6" x 24" and the green one is 8" x 24". I love the width of the green one for cutting larger strips, and the markings are very fine so I feel like I can cut very accurately. The Omnigrid is good, but it took a bit longer to get used to lining up my fabric with the markings. I guess what I'm saying is there are so many different rulers around, and some may work better for you than others.
One thing that has made a world of difference for me is the little round non-slip stickers you can see at the corners and half-way down these rulers. Before I started using these, my rulers would often slip a little at the top of the fabric so my cut wouldn't be completely straight. I know you can buy non-slip rulers, but if you are like me and have slippy rulers, I would seriously suggest investing in some non-slip stickers.
Dear Leanne and Jess, I find it difficult to square up yardage before cutting it into strips, especially in cases where the selvedges don’t meet up through the whole piece of fabric.
This is such a great question, and brings up a few other points to keep in mind when cutting fabric. Before you start cutting, make sure to press your fabric well. When you fold it in half lengthwise (along the natural fold where it has come off the bolt), your selvedges should meet at the top. If they don't you might need to move the layers of fabric slightly sideways in opposite directions to make the selvedges meet (ie move the top layer to the right, and the bottom layer to the left). If you are still having difficulty making the selvedges meet up, you might consider pre-washing the fabric as this can help relax the warp and weft threads and bring them back into alignment. It is also worth looking at the grain of the fabric - the grain line should run parallel with the markings on your ruler.
To square up fabric, I place my folded fabric (ie a half yard/yard) on my cutting mat with the folded edge closest to me, and the selvedges at the top of my cutting mat. In the photo below, the arrow is pointing to the bottom edge of the fabric, which should be carefully aligned with ruler markings. When using Omnigrid rulers, I like to use the smaller dots and lines rather than the wider 1" markings, as I feel like I can see where to line up the fabric better.
Here you can see a closeup of how the grain of the fabric is aligned with the markings on the ruler.
And here you can see a closeup of the folded edge of the fabric lined up with my ruler markings. I will be cutting 5 1/2" strips, so I have given myself a little lee way to square up the edge on the far left. You can see I have lined up the small black dots along the bottom edge of my fabric.
Once I'm happy that everything is aligned as it should be, I make the first cut, a little over 5 1/2" in from the left hand side. I have moved the larger piece of fabric to the side - but normally I would keep cutting strips from the left edge, since it has just been squared up. You will need to periodically re-square this leading edge, especially if you're cutting wide strips. After a couple of cuts, check your leading edge is still square, and if not, you may need to square it up again.
I do take that first strip and square it up first though, by flipping it over (so the square edge is at the left).
Then I take my ruler, and carefully align the 5 1/2" markings with the left hand edge, and align the bottom edge with some of the horizontal markings (again, I'm using the smaller dots rather than the darker lines). Once these are aligned, I make a second cut to produce a 5 1/2" strip.
To cross-cut (or sub-cut) these into squares, I lay the strip horizontally across my mat with the selvedges on the left, and make my first cut far enough from the left hand side that I will be able to discard the selvedges but still have a 5 1/2" square.
One other aspect of quilting which can make a huge difference to your accuracy is making sure you are sewing with an accurate 1/4" seam allowance. Many of you who responded to the questionnaire said you know how to check your seam allowance, but if you would like to learn how to Amy has written an excellent tutorial. This is the tutorial I have used several times to check my seam allowance, so rather than reinvent the wheel, I'll send you to Amy's blog ;o)
I hope this was a helpful post - if you have any questions please let me know!