Thursday, October 25, 2012

Foundation Piecing: Square In A Square Tutorial

Use pre-cut square and triangle patches to precision-piece this classic block. Because you stitch on the printed line, your points will be perfect, and your blocks square! Email Jodi ( to receive a PDF file to print the 3" foundations used to make this table mat. Practice with them first, if you like, or perhaps you'll be ready to piece project blocks now. Choose varied scraps in "light" and "dark" groups, use a one color scheme like this one, or simply jumble a varied color selection.
This project uses 3" foundations, and is approx. 14" x 14" finished size.

Step 1. Trim foundation COPY a scant 1/8" beyond outer solid (final trim) line.

Step 2. Next, use a straight edge (bookmark, postcard, small flat ruler) to make a guide edge to crease the foundation on all inner SOLID lines. Note how the foundation is being folded so that printed side of foundations are on the inside

Step 3. Measure patch #1 (center square) size, outlined in red here. Cut designated fabric patch with 1/4" + 1/4" seam allowances added to that size, or 2" for this project block.

Step 4. Turn foundation so printed side is DOWN. Attach fabric patch backside to backside of foundation using fabric glue stick - just a dab will do. The fabric edges should extend beyond the area's creased lines approx. 1/4".
Here is patch #1 in position on the BACKSIDE of the foundation.

 Step 5. Turn foundation over to be print side up. Fold at crease between patch #1 and patch #2. Use a rotary ruler and cutter to trim excess fabric patch away at selected seam allowance width. Repeat this for remaining 3 sides of square. For most projects, this would be the 1/4" previously referenced. Here, I am using the "Add-An-Eighth" ruler which has a raised lip 1/8" in from right edge. When I align it at the crease, that lip "catches" at fold to help me trim at exactly the right place. Eighth-inch allowances work well for miniatures or small scale blocks. Use the "Add-A-Quarter" ruler if you prefer the larger allowance.
Step 6. Analyse for information to pre-cut the triangle patches for the first row (#2-5). Here, one of those triangles is highlighted. With the 1/4" line of the ruler at triangle "square" edge, I can estimate that a 2" half-square triangle would be about right. Round slightly higher for security, such as 2 1/4", if desired. At right, two fabric squares are cut, then cut on the diagonal to produce the 4 patches needed to complete this round of one block.
Step 7. Fold over the diagram on the same line as step 5, for patch #2. (Here it is highlighted in red on front and back of the sample foundation.) 

 Step 8. With diagram folded, visualize the triangle shape needed to be underneath  the crease-defined focus area (#2 this time as marked in red). Place the cut triangle face up on the table. Position the red-lined shape over cut triangle and adjust so crease lines of diagram fall within cut edges. Both face fabric surfaces will be touching. When adjusting is done. carefully unfold diagram and pick up the foundation and patches. Take care that nothing shifts. (You can just see the white edge above left thumb, showing the patch aligned correctly underneath foundation.)

Step 9. Move to the sewing machine. Adjust the stitching length to about half the length of the usual straight stitch used in conventional piecing. You can see the stitch length in photo for Step 14. (For regular stitching on my Pfaff machine, I usually set the stitch length at 3+. For foundation piecing, I set it at 2.) Short stitching helps perforate the paper for easier removal later. Working with miniatures, it also makes the seam more secure for narrow-cut allowances.
Stitch, beginning 2-3 stitches before the diagrammed line begins (the line between what is already in place and what is being added). Stitch across the line, making the needle pierce the layers exactly ON the line. Stitch 2-3 stitches beyond the end of the line. Pull away from machine, clip threads, etc.

Step 10. Press triangle patch #2 back. 

Step 11. Move to rotary mat. Fold back on stitching line. Use Add-A-Quarter ruler to trim away extending triangles tips.

Continue adding the first row of triangle patches #3-5 in the same manner, repeating steps 8, 10-11. This photo shows row 1 complete.
Step 12. Measure the target triangle and determine "squares" cut size to pre-cut outer row triangles patches #6-9 as previously done in step 6 for first triangles row. The extended seam allow. on the straight inner seam edge hits the ruler near the 3" mark. Therefore, two 3" square patches will work to cut, then subcut diagonally into the needed large triangles. 

Step 13. Fold foundation on target seam line for patch #6. "See" the patch's triangle shape defined by creases (and here outlined in red). Place triangle face up on table, position target triangle over the patch, etc., as in step 8. Adjust, unfold, take to sewing machine.
Step 14. Begin 2-3 stitches before line, across line, end 2-3 beyond end of line, as in step 9.

Step 15. Press patch back. Turn work over on cutting mat, re-fold diagram and trim tips as in step 11. Repeat positioning, stitching, pressing and trimming of tips for #7.

Step 16. Add #8-9 in similar fashion. However, since these two are the FINAL patches to be added, the drawn seamline extends to the foundation outer line. For this block, seam line extends at both ends. Therefore, begin stitching from foundation paper cut edge, stitch along the line, then stitch off the cut edge at the end. (This makes the seam more complete and allows for easier paper removal.)
Step 17. Press the final patches back. Give the block a final good press. (I like to use steam or Best Press spray.)
Step 18. Turn the foundation over; place on the cutting mat. Use a rotary ruler and cutter to trim the block to its finished size by trimming exactly on the outer solid line. Try to "split" the line as you cut for increased precision.

Here is the final block, trimmed to final size.

Step 19. Remove the paper. Begin at the highest number patch. Fold back on the seam line, then begin at one end to tear away the paper section at the stitching perforations. Continue to the next highest number. Flex the fabric to release it from where it was previously connected at stitching. Fold and tear away. Keep working in reverse number order until all paper is removed. (#1 patch affixed with glue may need slightly more effort to remove.) Once paper is removed, handle patches with care to avoid stretching any bias edges.

Nine Block Table Mat Project
For the project shown at the top of this blog, prepare 5 "dark" blocks (right) and 4 "light" blocks.
Lay out the 9 blocks as shown. Join into rows, then join rows. Press seams in opposing directions. Add borders and/or posts as desired. 

For this layout, cut:
4 narrow borders 1" x 9 1/2"
4 post corners 1" x 1"
4 outer borders 2 1/2" x 10 1/2"
4 outer post corners 2 1/2" x 2 1/2"
binding of choice.

Layer, machine quilt, attach binding, and you're done.

Now, wasn't that fun!

Watch for other foundation piecing tutorials to continue 
learning more advanced layouts and shapes placement techniques.

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