Friday, April 11, 2014

Setting Triangles and Corners

Tomorrow's NewBee class will cover how to set blocks on point with corner and side/top triangles.

I was surprised at how many experienced quilters have never tried (or succeeded) in setting blocks on point because of the intimidation of calculating the size of SQUARE to cut the triangles from...

So, for those of you (like me) who are seriously math challenged.... here is a little pdf chart to help you out -
setting triangles and corners chart:  Let me know if you cannot 'copy & paste' this to a document of your own...  hopefully this will copy and paste for whatever computer software you are using.
 Note the 'SAFE CUT' column is for you to insert a size that you feel comfortable cutting... not all rulers allow for a 1/6th of an inch measurement!  I recommend rounding up to the next 1/4" if you are not confident of measuring that precisely.

I prefer to round up to the next 1/4" for measurements with 1/8" as well.
So, for a measurement of 8 3/8" I will cut squares of 8 1/2" to give myself a bit if breathing room.  I can always trim it down a sliver if there is excess.

My blocks have a FINISHED measurement of 12" - so I will cut 2 squares for the corners at 9 1/2"
(rounding up from 9 3/8")
cutting those in half on the diagonal will give me 4 triangles of a comfortable size.

for the side setting triangles, I will cut squares at 18 1/4"
these will be cut X-wise to yield four triangles to fit along sides, top and bottom.
This will give me a little to trim from the corners after all the diagonal rows are assembled, but I'd rather trim a little off than come out short or wonky.

This chart was developed with the help of the free APP from Robert Kaufman - available for smart phones and tablets. Just  click on the highlighted text above or visit your device app store for your own version.  I have it on both my phone and my Kindle.  It comes in handy for estimating yardage - for instance, for this 12" quilt, I'll need four triangles cut from two 9 1/2" squares plus the 18 1/4" squares for the sides - I'll get 4 triangles from each of the squares...
(mathematically, these squares would be 18 3/16th - yeah, right...)
I know that I'll need 6 triangles for my chosen layout, but I still need to cut at least 2 squares to get those 6 triangles.  The sample below uses 8 blocks, 6 setting triangles and 4 corner triangles.
The quilt calc tells me that the 18 1/4" squares will need at least 1/2 yd of fabric, and the 9 1/2" squares will need 1/3 yd (if I were buy it at the quilt shop) - but I know from experience that I'll need one strip of fabric 9 1/2" and 1 full width strip 18 1/4" -
so I just add those two numbers together for a total of 27 3/4" of fabric (as long as it is full width!)
9+18=27 and 1/2+1/4=3/4 - total of 27 3/4"  - so I know that my 1 yard piece of fabric will be enough!

This will yield a quilt approximately 34" x 51" without borders.  A narrow 1" border will need 1/4 yd of fabric cut into 1 1/2" strips. 

with that border, the quilt will be about 36" x 53".
If I can find another fabric for an outer 2" border the quilt will then be 40" x 57".
That's a nice size for a charity quilt, btw.