Thursday, March 14, 2024

Two-Colour Mystery Week 3 - template paper HST

If you're sewing along with me in the Two-Colour Mystery quilt-along, you should find the next clue in your email inbox around 9 am CDT today.  This week's task is to make half-square triangle squares (HST) in two different sizes.

The pattern offers two methods to choose from.  If you have access to a printer or copier, I strongly recommend the method that uses the templates I included.  This method makes many perfectly sized and perfectly square HST at a time.

If you've used Thangles or any sort of triangle papers, you know what to do.  For those of you who have not, here's a quick look at the process.  It's all described in the pattern, but photos can illustrate this in more detail.

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I'm demonstrating with the template for HST1 in the pattern, which makes 16 HST at a time.

1. Print out the template as many times as needed to make the number of units you need.   Be sure to choose "no scaling" or "actual size" or "100%" in your printer settings. 

Paper template for HST, with rotary cutter ruler

2.  Measure the 1" box to make sure the template printed out the correct size.  The box should measure 1" on every side.

A rotary cutting ruler beside a printed 1" square to measure accuracy of scale of printed template

2. Trim the excess paper outside the grey area.  This can be a rough cut.  It doesn't need to be precise.

Rotary cutter and ruler and HST template paper showing cut away grey margins

3.  Layer your fabrics, right sides together, followed by the paper template, right side up.  To plan ahead for pressing to the dark side later, layer fabrics as shown, dark on the bottom, followed by the light, then the paper.  You can pin the layers in place if you wish.

dark fabric, light fabric and HST template paper layered together.
hand separating layers of fabric and paper to show proper orientation (bottom fabric face up, top fabric face down)

5.   Decrease your sewing machine's stitch length to make it easier to remove the paper later.  I set mine to 1.5 on my machine.  Sew through the three layers, sewing on every dashed line on the template.  It's OK to stitch in the grey margins to travel to the next dashed line.

HST paper template after stitching on dashed lines
Stiches over the dashed lines and in the grey margin of HST template papers


6.  Carefully trim away the grey margins, keeping the cuts on the solid lines.

Rotary cutting ruler and cutter beside stitched layers of fabric and paper template, showing grey margins trimmed off.


7.  Cut on all the solid lines.  Start with the vertical and horizontal lines, cutting precisely on the lines.  Cut on the diagonal lines last.  These cuts don't need to be as precise, as they're in the seam allowance.

HST template cut apart on vertical lines
HST template papers sandwich cut along horizontal lines
HST template sandwich cut along all solid lines

10.  Leaving the papers on to stabilize the fabric, press the seam to one side,  Once the unit is pressed,  tear away the paper.  Folding and creasing the paper along the seam makes it easier to tear away the paper.

3 HST fabric side up and  1 HST paper side up, before pressing.  2 HST pressed open.  Torn off papers from two HST.

11.  Trim away any dog ears.  You can use a rotary cutter or scissors.  I find scissors to be faster for this, but do what's easiest for you.
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1 HST with dog ear, 2 HST with dog ears trimmed off,  small triangle dog ear trimmings and a pair of scissors to the right.

That's it.  I love that this makes many accurate units at once without having to trim down each unit individually.

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If you prefer to make your HST without papers, you can find a quick tutorial on the two-at-a-time method here.

If you're sewing along, let me know how things are going with your mystery quilt.  I've been seeing  many wonderful and varied fabric combination.  It's going to be so much fun to see how different the finished quilts look, based solely on fabric choice.

If you haven't signed up for the free quilt-along, there's still time to register and catch up.  Weekly instructions are sent by email, so you need to register to get your email address on the mailing list.

Happy quilting,
Joanne

NOTE: The templates I used are only available as part of the instructions in the mystery QAL third clue, which are available to those who have registered for the quilt-along.  If you registered but did not receive the clue, please email me (joanne@canuckquilter.com).  Otherwise, you can google "triangle papers" to find similar products to purchase.

PS  You are welcome to join my Quilting with Canuck Quilter Facebook group to share your progress.  Please note that to be admitted you must answer the questions you will be asked when you ask to join. This helps me keep the bots and fake accounts out of the group.  Thanks for understanding.

Making HST 2 at a time

In week 3 of the Two-Colour Mystery Quilt quilt-along, I offer two methods to make the required half-square triangle units (HST).  You can read about the template method I recommend here.  If you are not able to print out the templates for that method, or simply prefer not to use paper, you can make them two at time from squares.  

two white and dark teal half-square triangle square patchwork units

This technique is very common.  Many of you have probably used it in the past.  I'll share it again for anyone new to HST.  I'm also sharing a pressing tip and trimming instructions that help me with mine.

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1. Cut one square from each of two fabrics.  Technically, you can cut them 7/8" larger than the desired finished size of the unit.  For example, if you want a 2" finished HST in your quilt, you could cut the squares 2 7/8".  

Practically, it can be challenging to make these units perfectly square, so many quilters prefer to cut the squares 1" larger than the finished unit size to allow room to trim the unit square.  Using the same example as above, you would cut 3" squares for a 2" finished unit.  In my instructions for the mystery quilt, the cut sizes use the inch to allow trimming.  


2. Draw a diagonal line from corner to corner across the back of one of the squares.

A mechanical pencil with a square of fabric which has a diagonal line drawn on it from corner to corner.

You will need to stitch exactly 1/4" away from this line in a later step.  If you do not have a 1/4" presser foot that can help guide you in sewing that seam, I recommend drawing lines 1/4" on either side of the diagonal instead of a single line.  You can then sew directly on these lines.

A mechanical pencil with a square of fabric which has two diagonal lines drawn across it

3. Layer the marked square over the second square, right sides together.



4.  Sew a seam 1/4" away from the diagonal (or on one of the drawn lines if you drew two guides above).


5.  Repeat on the other side of the diagonal (or on the second drawn line if you drew two guides).


6.  Cut the unit apart between the two lines of stitching.



7.  Press the seams to one side.  

I prefer to finger press before using the iron.  I do this by opening the unit and running my fingernail along the seam to flatten it.  It's a bit like like creasing a fold in a piece of paper.  Doing this before using the iron helps me ensure as little fabric as possible is lost in the seam's fold.  Finger pressing is also less likely than a hot iron to distort the fabric.  Pressing (not ironing) with the hot iron after I finger press simply sets the fold I made with my fingernail.


8. You will need to trim the units 1/2" larger than your desired finished size.  In this case, for a 2" finished unit,  we need to trim the units to 2 1/2" square.  

Make sure to keep the seam on the diagonal, corner to corner, when trimming.  To do this, place the corner of a quilting ruler over the unit, lining up the marked 45 degree line with diagonal seam.


9.  Holding the ruler firmly in place, use a rotary cutter to trim away any excess fabric extending past the top and side of the ruler.


10.  Turn the unit 180 degrees.  Reposition the ruler so that the correct size marking (in this case 2 1/2" both vertically and horizontally) line up with the sides of the unit that you trimmed in the previous step.  The 45 degree marking on the ruler should line up with the seam.


11.   Holding the ruler firmly in place, use a rotary cutter to trim away any excess fabric extending past the top and side of the ruler.



12.  Repeat the trimming process for the second HST.  Your two HST are complete and ready to use in a block or quilt.



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There are other ways to make HST.  I encourage you to try various methods and choose the one that works best for you.  Just remember that if you are using a pattern, that pattern's fabric requirements and cutting directions are based on the HST method used in the pattern.  If you choose to use a different method, be prepared to make adjustments to the fabric requirements and cutting instructions if necessary.

After all that, I'd like to know if you have a favourite HST method.  Why do you prefer it?

Happy quilting,
Joanne

PS: If you haven't signed up for the free quilt-along, there's still time to register and catch up.  Weekly instructions are sent by email, so you need to register to get your email address on the mailing list.

PPS:  You are welcome to join my Quilting with Canuck Quilter Facebook group to share your progress.  Please note that to be admitted you must answer the questions you will be asked when you ask to join. This helps me keep the bots and fake accounts out of the group.  Thanks for understanding.

Thursday, March 7, 2024

What's a 1/4" Seam Allowance?

That pesky 1/4" seam allowance.  It's the standard in quilting.  It's the key to making things fit together.  It's everywhere, but what does it actually mean in practice and how do you measure it?

Here's the most important thing I want to say about the 1/4" seam allowance.


It isn't the distance from the edge of the fabric to the line of stitching.  It's whatever gives the correct result.

Then why is it called a 1/4" allowance?  Because 1/4"  is the measurement we use for the quilt math we do to figure out how make parts fit together the way we want them to.  

Quilt math works with a perfectly 2-dimensional design, but fabric and thread exist in a 3-dimensional world. When you press a seam, the thickness of the thread and the thickness of the fabric itself result in the fold taking up a bit of the fabric.


In the 3-D world, what's left in the block is what you originally cut, minus 1/4" and that little bit lost in the fold.  You'll need to take that little bit into account for things to work out as planned in a pattern.

Read on for more questions and do's and don'ts of seam allowances.


How do I measure the seam allowance?

If you sew two 2" squares together, you should expect  a 2" x 3 1/2" unit (mathematically, each square loses 1/4" into the seam, so 2" - 1/4" + 2" - 1/4" = 3 1/2").

So, sew two  2" squares together with what looks like 1/4" seam allowance, press the seam to one side, and measure the unit.  

  • If it's shorter than 3 1/2", your seam ate too much fabric.  Try again with a narrower seam allowance.
Seam allowance is too wide

  • If it's longer than 3 1/2", your seam didn't eat enough fabric.  Try again with a slightly wider seam allowance
Seam allowance is too narrow
  • If it measures 3 1/2", you've found the correct seam allowance.  You can mark the bed of your machine with tape or a stack of sticky notes as a guide to where to position the edge of the fabric to repeat that seam allowance, or take note of the needle position if you adjusted that to get the right seam allowance. 
Seam allowance is correct

You might be tempted to skip testing the seam allowance.  I get it.  Let's start building blocks already! Nevertheless, fudging might slow you down or mess you up later, and lead to more fudging to fix issues caused by earlier fudging, and so on, and so on.  I highly recommend taking the time now to save time later.


Can I just sew a "close enough" seam, as long as I'm consistent in all my seams?

Unfortunately, most of the time, this won't work out.  Sorry, it's a math and geometry thing.

For example, suppose a pattern includes this unit.

The pattern gives cut sizes that will make the two squares sewn together add up to a unit that is the same length as the rectangle it's being joined to, so they will fit together.  If the two squares add up to a shorter, or longer measurement, they just don't fit together, even if you use the same seam allowance on the horizontal seam.  The length will still be mismatched.  

Seam allowance too narrow

Seam allowance too wide

Can I just trim off any extra off the sides if parts don't quite match?

There are at least two possible problems with that approach.

Changing the dimension of a unit 

For example, in the unit I showed with a seam allowance that was too wide, trimming off the excess on the lower rectangle will make the unit measure 3 1/2" x 3 3/8" instead of 3 1/2" square.  It doesn't look like much of a change, but it's going to change how well it fits with other units in your pattern.  Over several units, it can really affect the total size in one or more directions, and possibly how square your project is.

Changing where seams fall in the unit

For example, in the unit I showed with the seam allowance that was too wide, shaving off some of the white is changing the proportion of the white piece.  When the green square and the white square were the same size, the seam was exactly in the center.  The white is now smaller than the green, and the seam is no longer in the exact center of the unit.

Depending on the design this might not be a big deal.  However, if the design needs that seam to line up in a particular way with some element in another unit, shifting that seam line away from the center might mess up the alignment.


Any other questions?

I think I've covered the basics. Do you have any other questions about seam allowance?  Add them in the comments or send me an email.  Now I'm off to sew the units for Week 2 of the Two-Colour Mystery.  After testing my seam allowance, of course.

Happy quilting,
Joanne