Impossible to get 128 7 1/4 square blocks from 2 5/8 yards
 

or I found it so. Is it possible? I cut from selvage to selvage, 7 1/4 inch strips; I pressed the stripes, stretched them out straight, and cut the 7 1/4 inch blocks out on 2 yards and only got 60 of the 128 needed. I think I need more fabric than the instructions said. Instructions said 2 5/8 of light fabric and the same amount for the dark to make the hour glasses...128 blocks. I failed and only got 60 out of two yards. Thanks for all your replies...you are the greatest at QB.

Are you sure you need 128 of these blocks? Perhaps they will be cut into smaller pieces, combining light and dark, and you will only need half as many?

It is certainly not possible to get all 128 from 2 5/8 yards, which is only 94.5". You can get at most 13 strips that are 7.25" wide, and each strip will yield only 5 squares, for a total of 65 squares. (Even if your fabric had a full 44 usable inches, you would only get 6 squares per strip, for a total of 78 squares.)

You need more fabric, but only enough for four blocks. If there are 128 blocks and they are half light and half dark, then you need half the number of each color. Guess how I know - I have two identical prayer quilts.

Will you be cutting the 60 in half? THat'll give you 120 from what you've already cut. You have 5/8 yard left which will be plenty to give you 4 more squares to cut into 8 halves. Am I following the logic here? It's not my forte but this seems reasonable.

It does seem logical; but it seem to defy that logic. One light is sewn to one dark, marked and sewn on the one diagonal line....on each side of that diagonal line and cut and pressed open. Again it is put front to front, watching where the light and dark placement is, and is again marked and sewn on each side of the line so an hour glass is formed, finishing as a 6 1/2 (finished six inch) block.

Thank you, dunster, for seeing my problem with the math... it fails to add up for me. I think I need twice as much as stated in the instructions (or that I got). If two yards yields 60 blocks, then I need twice that amount plus eight blocks more or two more strips beyond the two additional yards or 15 inches, making it 2 yards and 15 inches more fabric that I need to make the 128 blocks for the king sized quilt. The patterned blocks are every other block, so that makes the quilt 96 x 96 inches square. Now if I can find more of the light and dark fabric!

If you need a total of 128 hour glass blocks, then you only need 64 of the light and 64 of the dark. When you put a light square and a dark square together, mark, sew, press, cut apart, recombine, mark, sew, press, cut apart--you will still end up with two blocks.

ha, ha. i feel for you. the other day i got out my lovely 10 inch layer cakes i bought and thought about putting them together with my 5 inch charms. worked well until i remembered the charms will be sewn together and then will be smaller than the layer cake squares. rats!

Can you post a link to the pattern you are using?

If you washed your fabric, you may have "lost" a bit to shrinkage.

If it is not perfectly straight, you will lose some (assuming that being perfectly straight is important to you)

How much "usable" width do you have? Very few of my "quilting fabrics" are more than 42 inches wide - including the selvages?

Dunster's calculations are correct - assuming you have that much "usable" fabric available.

[ATTACH=CONFIG]582701[/ATTACH] Hour Glass Blocks cut as 7 1/2 inch strips from selvage to selvage; each two strips makes 12 blocks. Blocks finished (4) are on upper left looking at the pictures. There are enough strips to make 60 blocks the unfinished blocks are marked from corner to corner, the way they are sewn. Hope this helps to explain what I am doing and why I am getting 2 yards and 15 inches more of each fabric to finish making the 128 Blocks.

Look at the tan block on the bottom right with the X drawn through it. Only 2 of those triangles, say the top and bottom ones, will be used in an hourglass quilt. You don't need more fabric if you only need to make 128 hourglass blocks. You only need 64 7.5" squares of each color. But you also said that you need every other square to be a plain block. Are those from the same fabrics, or from different fabrics?