You already know how to make half square triangles.
The HST is the unit most quilters make more of than any other, and there are at least four ways to make one.
Somewhere around your fourth or fifth quilt the techniques stop being separate lessons and start being choices. The question is no longer how. It becomes which one, and where. Hovering Hawks is a good place to meet that question, because a single 12 inch quilt block wants two different HST methods, and using the wrong one in the wrong place will show up in the finished quilt.
Hovering Hawks at a glance
- Finished block. 12 inches. The block works at any size divisible by four.
- Grid. Four by four. Sixteen units, each finishing at 3 inches.
- Units. Ten half square triangles and six plain squares.
- Difficulty. Confident beginner. Every seam is straight, there are no curves and no set in seams. What the block asks for is accuracy, not a new technique.
- Fabric. Three fabrics: a light, a medium and a dark. A fat quarter of the dark and a fat eighth of each of the other two is comfortable. Cutting from scraps, the largest single piece you need is 7 3/4 inches square.
- Equipment. Rotary cutter and mat, a long ruler, a square ruler with a 45 degree line, a marking pen that shows on the back of light fabric, and an iron.
- Methods used. Magic Eight, four at a time, webbing the rows, nesting seams.
- Time. An evening for the first one.
Yvonne builds the whole block in the video below. The written version follows underneath, with the arithmetic set out so you can come back to it at the cutting table.
What the Hovering Hawks quilt block is made of
Hovering Hawks is a classic four by four quilt block. Sixteen units, arranged so a diagonal line of colour runs corner to corner through the middle of it.
Six of those sixteen are plain squares: two light ones in opposite corners, and four dark ones along the diagonal. The other ten are half square triangles, and they are what carry the movement.
Look at the diagram and count the triangles by colour. Six of them share one fabric pairing. Four share another. That difference in quantity is what decides the method, and it is the whole reason this block is worth making as a lesson rather than just as a block.
What you can make with the Hovering Hawks block
One block is a cushion front or the panel on a bag. The interesting question is what happens when you make several.
Because the diagonal runs corner to corner, the blocks talk to each other across the seams. Set them all facing the same way and the diagonals join into one long line down the quilt. Turn every other one a quarter turn and the line becomes a zigzag. Turn them in pairs and diamonds appear where four corners meet. Same sixteen units every time, three different quilts.
At 12 inches finished the arithmetic is easy. Twelve blocks in a three by four setting make a 36 by 48 baby quilt. Twenty blocks, four by five, make 48 by 60, which is a proper throw. Thirty blocks, five by six, make 60 by 72 and cover a single bed. Add sashing between the blocks and the diagonals stop meeting each other, which is worth deciding before you cut the sashing rather than after.
This is why quilters keep coming back to the block. Set several together and the diagonals make secondary patterns nobody drew into the block, which is the same trick that makes so many half square triangle quilt patterns work. You get more design than you paid for.
Where the name Hovering Hawks comes from
The block is older than the name. Barbara Brackman catalogues it as BlockBase number 1323, and records that it was Ruth Finley who called it Hovering Hawks, in 1929.
A hawk takes smaller birds, so the word travelled easily to men who took things. The Jayhawkers came out of the Kansas troubles before the American Civil War, and once the fighting started the name was pinned on raiders of every kind, on both sides.
Brackman gives this block a chapter in her book Civil War Sampler, where it is number five, and the two accounts she collects there are worth knowing before you sew one.
Roxanna Cole, in North Carolina, wrote about soldiers who came to her house and, in her words, "demanded quilts and comforts". She told them she had none she could spare. They answered that it made no difference, and to go and get two. Her diary survives in Thomas Felix Hickerson's Echoes of Happy Valley.
Anne S. Frobel, in northern Virginia, had the household silver buried in 1861 and wrote of the soldiers who came looking for it as spoonhawks.
Whether the women who first pieced this block had any of that in mind, nobody knows. But the quilts in those houses were among the first things anyone asked for, and that is a quiet thing to carry to the machine.
Four years after Finley, the pattern appeared in Nancy Cabot's column in the Chicago Tribune, on 8 April 1933, with a second name attached: Triple X. Cabot said it had been handed down from early New England days and described the triangles as birds, which is at least a consistent story.
Now the warning, because this is where people get caught out. Hovering Hawks is not one block. It is a name that has been attached to several.
The one on this page, and the one in Brackman and in Cabot, is the four by four with ten half square triangles and six plain squares. Brackman's own cutting list in Civil War Sampler asks for six plain squares and ten squares cut into twenty triangles, which is the same block arrived at by a different method. Elsewhere you will find a Hovering Hawks that is a nine patch with Birds in the Air units in the corners, which is a different block and needs different cutting. If you are working from a pattern you found somewhere else, count the units before you cut. Sixteen in a four by four grid means you are in the right place.
One more thing follows from those dates. A block published in 1929 and again in 1933 belongs to everybody now. The geometry is free to use, to draw and to teach. What is not free is a living designer's written instructions, diagrams and photographs. That is why every diagram on this page was drawn by us from the block itself, and why the video is Yvonne's own.
Every size in the quilt block comes from one number
Yvonne makes hers at 12 inches, and that single decision sets everything else.
A four by four grid at 12 inches finished means each unit finishes at 3 inches. Add the seam allowance and every piece in the block is cut or trimmed to the same size, 3 1/2 inches unfinished. The six plain squares are cut at 3 1/2 inches straight from the fabric. The ten HSTs have to arrive there by a longer road.
If you want a different block size, divide by four and start again. A 16 inch block wants 4 inch finished units, so 4 1/2 inches unfinished, and every formula below takes the new number.
The Magic Eight, for the six matching units
The Magic Eight starts from two squares and gives you eight matching HSTs in one pass. When you need six, that is the obvious choice, with two spare for the next block.
The sizing is arithmetic you can do at the cutting table. Take the finished size you want each unit to be, double it, then add 1 3/4 inches for the seam allowances. For 3 inch finished units that is 6 plus 1 3/4, which is 7 3/4 inches. Yvonne cuts hers at exactly 7 3/4 and points out you can cut at 8 inches instead if you would rather have room to trim.
On the back of the lighter square you draw a diagonal line in both directions, so the square carries a large X. Then a horizontal and a vertical line through the same centre point.
Those two straight lines are cutting lines, not sewing lines. It is the detail people get wrong the first time, and it costs a whole square when they do.
Her sewing machine has the quarter inch foot on it with the guide removed, and there is a reason. On this method the seam runs across the middle of the fabric rather than along its edge, so a guide has nothing to run against and only pushes the fabric around.
Sew a quarter inch either side of both diagonals.
Then cut on the straight lines, then cut on the diagonals, and eight units fall out of it.
One thing worth stealing from her: centre the sewn square on the mat and pick your numbers so the halfway point is easy to find.
It removes the arithmetic at the moment you are holding a rotary cutter.
If you have not met this method before, our Magic Eight walkthrough covers it on its own.
Four at a time, for the other four
The four at a time method is the one where you put two squares right sides together and sew a quarter inch all the way around the outside. Then you cut the sewn square in half diagonally, twice, and four units fall apart in your hands.
The sum is different. Take the finished size, add the half inch of seam allowance, and divide by 0.625. For 3 inch finished units that is 3 1/2 divided by 0.625, which is 5.6, and Yvonne rounds up to 5 3/4.
She rounds up on purpose, so the four units come out slightly oversized and get trimmed down rather than arriving short. There is more on the method in our four at a time tutorial.
Four cuts, four units, no waste. It is the obvious choice when you need exactly four of something.
The bias rule that decides where each HST goes
Here is the part most tutorials skip, and it is the reason this block teaches something.
Ask yourself where the bias ends up.
In the four at a time method you cut the sewn square along both diagonals. The original outside edges of the squares were on the straight of grain, and they become the seam. Every edge on the outside of the finished unit was made by a cut across the weave.
Yvonne demonstrates it by pulling on the edges. The outer edge of a four at a time HST stretches. In a Magic Eight unit it is the other way round: the outer edges come from the original edges of the squares and stay put, and the bias is safely inside the seam.
That single fact tells you where each unit belongs. A stretchy outer edge is fine when the unit is going to be sewn to something on all sides, in the middle of a block, where the neighbouring seams hold it steady.
It is a problem in a corner, where that edge sits on the raw edge of the whole block and gets handled, pinned and pressed with nothing to stabilise it.
So in Hovering Hawks the four at a time units go inside, and the Magic Eight units take the positions nearer the edge. It is the same principle we come back to in why one quilter stopped using four at a time, where the same method is the wrong tool for a different block.
Pressing without stretching the seam
Press to the dark, as always. The seam on an HST runs on the bias, so how you press it matters more here than almost anywhere else.
Set the seam. Open the unit and give the fold a small finger press to start it.
Then hook the point of the iron into the corner and press straight up, perpendicular to the bias rather than along it. Pressing along it is how a perfectly cut unit turns into a slightly rhomboid one.
Yvonne's Magic Eight units came off the machine at exactly 3 1/2 inches, so all that was left was clipping the dog ears. That is what a well drawn line and an honest quarter inch get you.
Trimming, and the sixteenth of an inch that adds up
Trimming an HST is one movement. Lay the 45 degree line of a square ruler along the seam, line the edges up on the 3 1/2 inch marks, and cut.
If the corner is not square to begin with, do it in two passes instead. Square that corner first, keeping the whole unit outside the 3 1/2 inch line so you still have something to cut.
Then turn it around, put the 45 degree line back on the seam, and trim to size.
The number worth carrying around is this one. Yvonne measures a unit that is a sixteenth of an inch too big and says out loud what it means: sixteen of those and your quilt is a whole inch out. The next unit she checks is an eighth off, and at an eighth it takes only eight of them to lose the same inch.
That is more useful than being told to be accurate. A sixteenth of an inch looks like nothing on the cutting mat. It stops looking like nothing when you have sewn sixteen units together and the row will not match the row above it.
If you do not own a square ruler at this size, the rulers collection has the ones with a 45 degree line through the middle, which is the line doing the work here.
Laying out the quilt block before you sew anything
Sixteen units, four rows of four, and every triangle pointing a particular way.
Start with the two light plain squares in opposite corners. Put the four dark plain squares on the diagonal between them.
Then fill in the ten HSTs around that skeleton, and check every one against the diagram before you pick anything up. Turn a single unit by accident and you will not notice until the block is finished.
Webbing the rows so nothing gets turned
Yvonne's answer to that risk is webbing, and it is worth the small change in habit.
Instead of sewing each pair and stacking them, fold the first column onto the second and sew all four pairs without cutting the threads between them.
The units stay joined by those threads, in the order you laid them out, and you can open the whole thing back out and check the layout at every stage.
Then the third column goes on, then the fourth, and nothing has ever left the grid.
She mentions the alternative too, which is to see the block as four four patches and build those first. Both work. Webbing is what protects you from the mistake that costs the most time, which is the block that is finished and wrong. There is more on the habit in our notes on pressing and webbing.
One practical note. As the rows get long, the bottom of the block hangs off the machine and drags itself out of alignment. A pin or a clip at the lower joins holds everything where you put it while you move the block around.
Nesting the seams, and the little cross
Press the first row one way, the second the other, the third back again. When two rows meet, the seam allowances inside them face opposite directions and lock together. You feel it with your fingertips before you pin.
Yvonne presses this block from the back, because with this many angles it is easier to see where everything is going.
Now the join itself. At each intersection, look for the little cross where the horizontal seam meets the diagonal one. That crossing point is where the needle should land, or one thread to the outside of it so the seam still has room to press open.
Hit it and the points match. Miss it and you see it immediately, either as a point with its tip cut off or as a sliver of extra background before the point begins. Our guide to getting your quilt points to match goes further into it.
Where the rows meet, some units have a bias edge and some do not, and they will not always be exactly the same length. This is the moment quilters stretch the bias unit to make it fit and then wonder why the block bows. Do the opposite. Feed the bias unit in a little and give the straight of grain unit underneath a gentle pull, so the two meet in the middle.
The stable piece gives. The bias piece is not asked to give at all.
What to cut for one 12 inch quilt block
Two squares at 7 3/4 inches, one light and one dark, for the Magic Eight run. That gives you eight units and you need six.
Two squares at 5 3/4 inches, one medium and one dark, for the four at a time run. That gives you exactly four.
Six plain squares at 3 1/2 inches: two in the medium fabric for the opposite corners, four in the dark for the diagonal.
You also need a square ruler with a 45 degree line, and the willingness to trim. Yvonne trims even when the units come out right, because checking costs seconds and unpicking costs an evening.
Other blocks built from the same units
Once you have a pile of half square triangles trimmed to 3 1/2 inches, Hovering Hawks is one layout among many, and the arithmetic never changes.
Four HSTs in a two by two grid, all turning the same way, give you a pinwheel. The same four turned differently give you broken dishes. Put four HSTs on the sides of a nine patch with plain squares in the corners and you have a friendship star.
None of those need a new formula. They need a different layout on the design board, which is why a batch of HST blocks is never wasted even when you change your mind about the quilt.
If you would rather follow a whole quilt than design one, two of the free patterns in our library are built almost entirely from half square triangles: Flow runs them through a rainbow, and Formation does the same in batik earth tones. The rest of the half square triangle quilt patterns in the library all start from the same unit.
Questions about half square triangle quilt blocks
What is the Magic Eight method for HSTs? Two squares right sides together. Draw both diagonals on the back of the lighter one, then a horizontal and a vertical through the centre. Sew a quarter inch either side of both diagonals, cut on the horizontal and vertical, then cut on the diagonals. Eight matching HSTs, one pass.
What size do you cut for half square triangles? It depends on which HST method you use, which is the part that catches people out. Two at a time: finished size plus 7/8 inch. Four at a time: finished size plus 1/2 inch, divided by 0.625. Magic Eight: finished size doubled, plus 1 3/4 inches.
What is the formula for half square triangles? There is no single HST formula. Each method cuts a different number of units out of the same two squares, so each has its own sum. Write the three above inside the lid of your thread box and you will never look them up again.
How do I make a quarter square triangle block? Make two HSTs first, put them right sides together with opposite fabrics facing, and cut them again on the other diagonal. Cut the starting squares at the finished size plus 1 1/4 inches to allow for the extra seam.
Can I make Hovering Hawks with all one method? Yes. Make all ten HSTs with the Magic Eight and accept the waste, or make all ten four at a time and put the bias where it can be held steady. The block does not care. The reason to use both is that you are practising two methods on one block and finding out where each belongs.
One block, then another
Make one. Then put it on the floor next to a second one turned a quarter turn, and watch the diagonals meet across the seam.
That is the moment the block stops being an exercise and starts being a quilt. It is also the moment you find out whether your sixteenths were honest.
Yvonne has a sign on her design wall that says "my quilt, my rules". She means it about patterns: a pattern is a jumping off point, not a law, and if you find a better idea halfway through, it is your quilt. The bias does not negotiate. That one is worth learning once and keeping.
Marbelia Fernandes
The Fabric Hut Co-Founder
P.S. When Yvonne finds a join that did not quite match, she does not unpick the whole seam. She clips every fourth or fifth stitch for about an inch either side, pulls the thread out, and resews just that stretch. Two minutes instead of twenty, and nobody will ever know.
Historical sources for this block: Barbara Brackman, Barbara Brackman's Civil War Sampler, block 5; Thomas Felix Hickerson, Echoes of Happy Valley; M.H. and D.M. Lancaster (editors), The Civil War Diary of Anne S. Frobel.
