At times, even experienced quilters shy away from on point quilting, simply because they don’t like dealing with the calculations. Traditional quilt blocks like the basket block and bride’s bouquet are designed to be set on point, while other traditional blocks, like the nine-patch block, look great whether they are set on point or straight.
In all actuality, on point quilting is not that different from quilting with traditional square blocks. Eventually, however, you’ll run into the border of your quilt, and those blocks will need to be set with triangles of the correct size.
Calculating the Triangles
Here are some easy calculations to help you figure out the triangle settings for your next on point quilting project.
Block to Block / No Sashing
If you are making an on point quilting project that is block to block with no sashing (like the “Basket Quilt” by bluetwin above), follow the calculations for corner and side triangles directly as written below.
Quilt Blocks with Sashing
If you are making an on point quilt that has sashing between the blocks, add together the finished sashing to the finished block size before calculating triangle sizes. For example, in the “Jungle Lattice” quilt pattern featured at the top of this post, the 4 1/2” finished squares have a 1” finished sashing. Adding those together, you’d get a 5 1/2” finished block size.
– Formula: Finished block size (divided by) 1.414 (+) 7/8”
– Cutting: Cut a square the size of the number you get above, and cut it in half ONCE diagonally, to make your corner triangles.
– Example: Finished block size 15” (divided by) 1.414 (+) 7/8” = 11.48”
Round up and cut two squares 11 1/2” and cut each in half ONCE diagonally. Makes two corner triangles.
– Formula: Finished block size (x) 1.414 (+) 1 1/4”
– Cutting: Cut a square the size of the number you get above, and cut it in half TWICE diagonally (in an “X”), to make your side triangles.
– Example: Finished block size 15” (x) 1.414 (+) 1 1/4” = 22.46”. Round up and cut squares 22 1/2” and cut in half TWICE diagonally. Makes four side triangles, and you may repeat until you fill in all the edges of your quilt top.
If you’d like to skip the math all together, Quiltville shares a cutting chart for on point quilting with corner and side triangle sizes that go along with 3” to 16” finished blocks. It’s an excellent resource, and one you can use to double-check your calculations.
Assemble the Quilt Top
Assemble the rows of your quilt by attaching the side triangles to the ends of each row. When attaching the corner triangles, use a rotary cutter and ruler to trim the edges of the quilt top, making sure to leave 1/4” seam away from the corners of your blocks.
Quilting Board suggests using acrylic cutting templates for cutting the setting triangles, if you’d rather not use the squares and slicing method described above. If you use a cutting template rather than the squares and slicing method detailed above, just remember that you want to keep the straight grain of the fabric facing the outside border of the quilt top. This will prevent a rippled effect when adding your final border.
Have you tried on point quilting? Why or why not?
Be sure to come back to the Craftsy blog tomorrow to enjoy the Free Pattern Friday roundup of fabulous FREE quilting patterns.