The Lily Pad: The Journal of White Lotus Quilting

More Atomic Quilting: the three-part triangle

In today’s exciting episode of atomic quilting, we’re going to consider a hybrid atom that is really very useful: the three-part triangle.  (In Thangles instructions this is often called a ‘tulip square.’)  And we’re going to look at this atom in the context of building a Behemoth block, from month #2.  Yes, I’ve finished mine (it was supposed to be for November), and no, I haven’t posted any pictures yet, at least not here.  But the whole photostream is on flickr so if you click on that link, or any of these pictures below you’ll get to the album full of Behemoth pictures from October and November.

It’s the ‘card trick’ block that’s so interesting, and I made it last, but I’m going to show it to you first.

card trick block assembly

In the Behemoth directions, Julie shows this as a three color block, and I made it with five colors.  Take your pick of how you’d like yours to look.  I made the block with Thangles but of course you can use your favorite way to make half-square triangles and related pieces.  With the Thangles I made make all the pieces from one strip size; depending on the method you may need to cut up to three different sizes of squares or triangles.

If you break this block down into quilting atoms, it contains three different atoms, each successively more complex, although they each finish out to the same size.  There are four half-square triangles (HST) on the corners (one each of each colored ‘card’ and common background); one quarter-square triangle (QST) in the center (with four different colors of the ‘cards’); and four three-part triangles (if you can think of an appropriate abbreviation let me know), each one containing two colors of ‘cards’ and the common background color.

Three-part triangles are like a half-square triangle, except that one half is divided again, usually into a light and a dark.  They are made similarly to quarter-square triangles in that a finished half-square triangle is sewn again, this time to a solid square (instead of another half-square triangle, for the quarter-square).  Again I used Thangles for this step, so I wound up with one three-part of the appropriate size, and one smaller hatchling, for each color ‘card.’

With five colors, it can be a bit confusing, so here are pictures of the block in progress so you can see how I built the block:

card trick block assembly

First, I made the half-square triangles of the four colors plus the background.  I cut the Thangles paper into individual pairs, so when I sewed these, I wound up with two HST of each (I only show one here, in each corner).  I used all of them though, more on this in a moment.  Then I made the quarter-square triangle in the middle, by making two pairs of half-square triangles in light/dark combinations.  I then sewed one pair together for the center QST.  (The alternate pair will be spare.)  You wind up with one QST in the correct size, and one hatchling of smaller size, which is also spare.  These hatchlings, by the way, are the result of using only one strip size to begin with, rather than cutting each piece to different sizes.  I don’t mind them, and usually find other uses for them, but if they bother you, use a different method for your QST.

Here’s the quarter-square triangle and its hatchling:

card trick block assembly

Now comes the interesting bit.  I laid them out a little strangely, but it’s so that I can get the colors right for the three-part triangles.  I took the leftover half-square triangles from the block corners, that look like this:

card trick block assembly

And I put them next to their similar colors, in a sort of flying geese layout.  (Don’t worry, it will look wrong at this point.)  Then I cut solid squares of each of the colors for the cards, like this:

card trick block assembly

Then to make each three-part triangle, I laid the square over the spare half-square triangle, in the orientation I wanted to see it finish (to be sure I sewed the line correctly).  Here’s what I mean:

card trick block assembly

Once I knew where the color square needed to be placed, I stacked it on top of the half-square triangle and used Thangles paper to sew the diagonal seam.  I sewed the second seam for the bonus ‘hatchling.’  Here’s what it looks like with the Thangles paper:

card trick block assembly

Here’s finished three-part triangles in a different color set, one of the correct size, and one hatchling:

card trick block assembly

And here is the block with two three-part triangles completed (it’s their hatchlings below the block):

card trick block assembly

Cool, eh?  Once you finish all the three-part triangles, the block looks like the picture at the top of the post.  It gives the illusion of the color ‘cards’ overlapping each other, which I think is wonderful.  Sure, the block is fussy, and it takes a fair amount of diligence to get the colors right, but when you do, it’s an entertaining illusion.  And by breaking it down into component atoms, it makes the block construction simpler to understand, and scale up or down, as you choose.

The card trick block is part of the Behemoth BOM block #2 (in the lower left corner):

finished block #2

So if you haven’t started on your Behemoth yet, don’t worry!  Make the blocks in your own way and time.  You’re going to gain a month as  we’ll use December to catch up.  (I don’t know about any of you, but the snow/ice storm and ensuing power outage shredded my schedule last week!) I won’t post any of the third block until January.  We will still have the open sewing studio date in December, though, so feel welcome to come and sew on whatever blocks you’re working on.  And get your free teeny weeny holiday gift!

And in the meantime, enjoy the holiday season, and happy sewing!

The Mighty Half-Square Triangle

Next to the superhero square, the half-square triangle is probably the most important sub-atomic unit in quilting.  The half-square triangle appears in all sorts of patterns in lots of combinations, so it’s worth getting to be friends with.  In the Behemoth block, it appears in the Friendship Star, which is the second to last part of block #1.  So I feel compelled to try to explain it a bit even though it is a huge hairy topic in quilting, which invokes emotionally charged responses like in discussions of politics or religion.  And a little like religion, everyone is pretty much sure their way of making these little units is the best way.
Making the friendship star

Here are the beauties I sewed for the Friendship Star.  So let’s start with these as an example of the half-square triangle unit.   A half-square triangle is the triangle that happens when a square is divided along its diagonal.  That means that if you cut a triangle like this out of fabric, the long diagonal edge is on the bias.  And bias means STRETCH.  Fabric has the most give (distortion) along the bias.  So if you cut the triangles and sew them back together to make a two-triangle square (don’t worry, here’s where some of the confusion lies — this compound unit is ALSO called a half-square triangle, or HST), the piece will distort as you sew.  If you’ve starched the heck out of it, it might distort only a little.  But if your feed dogs are a little aggressive and the fabric has a lot of give, you’ll wind up with a diamond or trapezoid instead of a square.  WAH.  In the past I’ve trimmed many of these oddly shaped little units down to their more accurate size, but that means you have to start with bigger triangles than the match tells you, to accommodate the accumulation of sewing mistakes.

So here’s one place where I substantially differ from Bonnie Hunter, the genuis behind I don’t cut triangles first, unless it just can’t be helped.  I always sew first, then cut later.  If you sew the diagonal seam while the weave of the fabric is intact, it stabilizes the bias and prevents a lot of the distortion that happens when you sew on bias edges.  The other thing is that although you can mark your own sewing lines, and cut the odd size strips that HST’s call for, I have come to prefer sewing on pre-marked lines on Thangles paper, on normal pre-cut (by me or fabric companies) strip sizes.  It helps me make the most of my limited piecing time.

Making the friendship star

This is where I started for my Friendship Star adventure — by layering two identical size strips over each other, light over dark, and pinning on Thangles paper of the appropriate size.  Then I sewed on the dotted lines, cut on the solids, and after pressing produced the half-square triangles seen above.  Actually in the view of the HSTs above (first picture in post) I haven’t yet removed the paper.  If you leave the paper in when you press, that also stabilizes the bias and prevents distortions from the ironing.

The Friendship Star is a nine-patch block, with five plain squares and four half-square triangles.  The plain squares are divided into four dark squares and one light square (in the center) in this case but you could reverse the color balance and make the star look dark in a light background.  Here it is as a light star in a light background:

Making the friendship star

For a survey of half-square triangle construction methods, try this link: half-square triangle goodies.  Yum!  Lots of great stuff here.  There’s even triangle paper you can print out on your printer if you like that sort of thing!

After the Friendship Star, the only thing left in our Behemoth block #1 is two giant quarter-square triangles, which I’ll tackle in the next post.  And of course I’ll post a photo of the finished block #1.

Say sew happy, all!