After I wrote this post I went back to the internet to see if I could find the image that inspired me, and I discovered the name of the block is granny square, like the crochet pattern of the same name.
Directions (read them all first)
These are directions for making a quilt top. I intend to trim the sides and add a border, but there are other possibilities. It is about 64 inches square. If you use smaller squares you will get a smaller quilt.
At first I thought I should make individual blocks, surrounded by black diamonds, trim them square and sew them together. Then the black diamonds would be triangles sewn together. In fact, there are many directions on the internet that tell you to do exactly this. But I did it in a more complicated way for two reasons. First, I don't like the idea of throwing away bits of fabric. Second, sewing is tedious, and if it's complicated, it's more interesting. A third reason would be that sewing blocks together like this would introduce the difficulty of matching points at a place where six seams come together. Other people work around this by adding sashing. The benefits of working with individual blocks are that the blocks can be more easily arranged, sewing the blocks together is straightforward, and you avoid the problem of the top being skewed, which can happen when you sew all of the squares together in one diagonal direction and all of the rows in the other.
There are a few things that you have to have or be able to do if you want to make this top.
First and foremost, you should have experience and the usual set of quilting tools including an ironing board. You need have made a quilt top before.
Second, you must have some combination of patience, skill and doggedness. If you have patience but average skill and serenity that should be enough. But if you don't have patience then you will need both skill and doggedness, because sewing this thing together is tedious and prone to problems. The problems can be avoided if you're patient or extremely skilled.
Third, you need a design wall. I put a piece of felt on the wall with push pins and tape.
Fourth, you need to be able to make precise quarter-inch seams. Unless you have some reason to piece this by hand, you should have and know how to use a 1/4 inch presser foot accurately. If you don't sew this top together precisely, then it will be skewed. Mine is slightly skewed in the picture, but it will straighten out when I iron it. If your long seams are wider than the seams used to sew the squares together, you will not end up with a square quilt. If you don't understand this or don't feel confident that you can avoid this problem, you may be very disappointed with the outcome and should use a different method.
Fifth, you have to have enough squares. You will need 36 sets of 8 light to medium squares, 36 sets of 4 light, medium and dark squares that look good together with the sets of 8 squares, and 36 single squares for the middle for a total of 494 squares. You will also need 217 black squares. You can use a color other than black, just make sure the sets of 8 aren't the same color. If you want to cut your squares from lengths of fabric rather than use up a motley collection, just choose whatever colors you like.
I sorted my squares by color first, and then for each color I tried to find groups of 8. There were very few of these, so I also made groups of 8 from squares that were very similar in color and value (light or dark). I sorted the squares that couldn't be made into groups of 8 into groups of 4. A few didn't end up in any group, so I left these aside for the middles. When I was done with this step, I had many more groups of 4 than groups of 8, so I had to go through the groups of 4 again and find sets that matched less well. Then I sorted by color and value again. My work table was a bit of a mess at this point, so I matched the groups of 8 and groups of 4 in two passes. First, I sorted the groups of 8 by light and medium cool colors (green, blue, purple, black and gray). I sorted the groups of 4 by light, medium and dark cool colors. Then I was able to match the groups in a way that I liked. I did the same thing with the warm colors (red, orange, brown, yellow and white). Once I had all sets of 8 and 4 together, I arranged the squares into a block (Step 1) and chose a middle square.
Important: Unless you have another workable idea of how to put this thing together it is important in this step to lay the blocks out in the direction they will have in the final quilt. The instructions that follow assume you will not rotate the blocks when you are arranging them.
As you arrange the squares into blocks, stack them as show in the picture. The next step can be done faster if all the squares you have to sew together are in stacks.
Important: Sew pairs of squares first. Press all seams to the upper right. Then sew together 2 or 3 of the pairs to make the long rows, and press all those seams to the lower left. Then each square will either have its seams both pressed out or both pressed in. The reasons for doing it this way are that all the seams will interlock when sewing long strips of squares together, and all black squares will have seams pressed in, which is what you want to have happen.
I actually took the picture from step 3, printed it out large on photo paper, and cut it into small squares, numbered on the back. Then I arranged the blocks the way I liked using the pieces cut from the photo and used the result to rearrange what I had on the design wall. Then I made some additional changes to get my final layout.
I learned everything I know about composition from my late great quilting teacher Kathleen Weinheimer. She taught me that you don't want the viewer's eyes stuck in the corners or the middle of the quilt, so I put more sedate blocks in these locations. I didn't put any of the really bright blocks along the sides, either. I didn't originally intend for my lightest blocks to form a sort of pinwheel, but when I shifted some blocks to get that result, I could tell it worked.
Step 5. Very important. Take a picture of your final arrangement. If you don't end up needing it, I bow to your Olympian skill level.
The next 5 steps describe how I sewed the squares into diagonal strips of varying lengths. Of course there are many ways to do this, so if you have some idea of how you would like to do it yourself, skip these steps. You will end up with short strips on the upper left and lower right, and long strips in the middle that extend from lower left to upper right. Please, please, please keep putting your strips back on the design wall as you go, otherwise you might end up sending bad feelings my way.
Step 8. Now sew together the strips from the first two and the second two columns, press and replace.
Step 9. Add the strips from the last two columns in the same way.
Step 10. Add a black square to the lower end of every strip, and press seams out. Add a black square to the upper left and lower right corners.
The next five steps describe how to sew together the diagonal strips. Again, if you know how you would like to do this, you can skip these steps.
Step 11. Sew together pairs of strips, carefully. First of all, in this step it is easy to sew two adjacent strips together on the wrong side. Another potential pitfall is to get the offset wrong - all pairs of strips will have different numbers of squares in them. So make sure you are sewing the strips together the right way. I did this twice and had to pick out four seams. I was lucky they were short seams, otherwise I would have had to be extremely dogged to finish this. Which I am, but it's no fun. To avoid mistakes, it helps a lot to have the picture of the layout handy.
Second, make sure your seams are precisely 1/4 inch. If you have any doubt, err on the scant side. Use a ruler to measure squares that don't look right, and if the finished side of the square isn't what you should have (2 1/2 inches in my case), do the seam over. Press all seams towards the shorter strip. Aside from being easier, this will help in two ways. The long seams will interlock when you are sewing panels together, and the seams will be pressed towards the black squares at the ends of each row.
In this step, I did not use pins. I used the interlocking nature of the alternating seam allowances to align my squares.
One thing I like to do is to sew strips together in ever-widening panels. That is, I like to sew pairs of strips together first, then pairs of pairs, then pairs of four strips, then pairs of eight strips, etc., until I only have two large pieces to sew together. But in order to do this, I have to start with exactly 4, 8, 16, 32, 64, etc. strips. This quilt top had 37 strips including the two black squares. What I did then was to sew as many pairs as I could to begin with (18 plus one left over), and then I sewed together some of the smaller strips in the upper left and lower right corners until I had exactly 16 sets of strips. I ended up with two triangular panels on the upper left and lower right and 14 sets of strip pairs inbetween.
Step 12. Sew together the 16 sets of strips to make 8 panels. At this point I started using pins. You might not have to, but it helps me a lot. I line up the edges by interlocking the adjacent long seams, and I line up the squares by interlocking the short seams. Continue to press seams towards the shorter pieces, away from the center diagonal.
Step 13. Sew together pairs of 8 panels to make 4 panels.
Step 14. Sew together the 4 panels in pairs to make two panels.
this one and this one. And the rest - well, I just did my best. I don't have a collection of 3-inch squares anymore, and I don't want to start one anytime soon. I have a whole bunch of 2 1/2 inch squares and strips that I have to deal with first.