Tuesday 17 November 2015

Blocks and Patterns and Calculations...

  and don't be afraid!

- this post contains affiliate links (indicated), which means I receive a small amount of the sale price should you wish to purchase (no pressure though). This makes no difference to the price you pay! All opinions are independent and my own -

Some years ago I was asked to write the pattern for a quilt I made. I set about drawing the steps, wrote the text and did the calculations. The pattern got written in the end, but those calculations! After all, this pattern was going out into the world, so the calculations had to be right. I know, I am a bit of a perfectionist at times, but really, they had to be right. There were the cutting instructions (sizes and quantities), and total fabric requirements (number of fabrics and amounts), and while I did not want to tell people to buy too much fabric, I definitely did not want to risk them buying fabric and finding out it was not enough! This feeling of responsibility led to a long time of calculating, and re-calculating, and going over it again and again... It took forever!

These days I seem to be making mainly quilts without commercial (or even any) pattern. Often I make it up as I go along, using whatever selection of fabrics I fancy from my boxes. I am not too upset if I miscalculate, or change my ideas, and I need more (or different) fabric. I just find some more that will go into the mix.

However, I also have some ideas for quilts that will not like that slapdash approach. I draw blocks that want to be made into quilts. I design quilts on paper that do need fabrics that are well coordinated. I stand in the quilt store and wonder how much fabric I will need for a project I have in mind... This needs planning. However, I now have found a great help!

When I was recently asked to review the "Quilty Math Workbook" (*affiliate link*) for Carrie of Carrie Actually, I jumped at the chance! And looking through the book was a light bulb moment. Or rather, a series of light bulb moments...

I had to get my colour pens out for this

The book comes as an e-book (PDF download) of 25 pages. And it is ideal to print off and keep in a folder. Since many copies of the work tables can be added you can make it into a personal resource for as many quilt designs as you can come up with.

The first section shows what you can do with the book. Carrie shows (with clear examples) how to use the diagrams to document your block and quilt design. And then she guides you step-by-step through the worksheets, helping with all the calculations. The worksheets are designed to help decide on quilt dimensions, and sizes for individual patchwork pieces. And from that on to the amounts of fabric you will need to buy (or gather...) to make the quilt as planned.

examples as shown in the Quilty Math Workbook

 Inspired, I worked out an example of my own:

block diagram

quilt diagram

The most attractive page for me is the Seam Allowance Worksheet. I can see a whole folder full of worked out block designs, with sizes and numbers of pieces all worked out, ready to make into a quilt:

The Seam Allowance Worksheet includes a sketch of the block

The next step is the Fabric Requirements Worksheet which guides you through the calculations for the amounts of fabrics required for your chosen quilt top. In her example, Carrie shows the requirements for one fabric, but my quilt didn't need that many fabrics, so there was space enough in the table to fill out all the requirements for my whole quilt top in the table.

Fabric Requirements Worksheet

The book includes explanations for the size of seam allowances for common shapes (squares, rectangles, Half Square Triangles and Quarter Square Triangles), but also a calculation for the number of equilateral triangles you can cut out of a fabric strip. So now it will be a breeze to determine the fabric requirements for that triangle quilt I have in mind...

Since I have not actually sewn the quilt top, I did not use the rest of the book (yet!). The workbook goes on to help decide the size of wadding (batting) needed for your top size, as well as how to piece the backing most efficiently, and how much fabric is needed for that. Lastly, the book guides you through the calculations for the binding (number of strips, amount of fabric) to finish off your quilt to perfection.

There are a few features in the book that I don't think I will use. There is a Quilt Size Worksheet which helps you decide on a quilt size that easily fit a precut wadding size. Since I most easily get my wadding from the roll this is not really relevant for me. And I skipped the Quilt Top Assembly Diagram, too. But I am happy to have found a resource that helps give me confidence that my quilty calculations add up. I will be writing up many more patterns for sure, and keeping them together in a folder to look through when I want to make a well-planned quilt.

For more details, or if you want to have a copy for yourself, the Quilty Math Workbook (*affiliate link*, opens in new window) is available from Carrie's Gumroad site.
With all that designing going on I better not forget to do some sewing as well...

Linking up with:
- Needle and Thread Thursday at My Quilt Infatuation
- Let's Bee Social at Sew Fresh Quilts



  1. Carrie's workbook sounds like a really helpful aid to quilters Sandra. Thank you for the review! Your impromptu design looks really like it would make an awesome quilt!

  2. This has been such an interesting post Sandra... what a great resource this book will be for those clever people who design their own quilts & want to be sure their calculations are correct!
    Lovely colours in your illustration!! xx


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