Cathedral window cushion

I'm going to be rubbish here, and I won't write my own tutorial.  Rather, I'll link to some people who have written very good ones: click here for PatchworkDelights, and click here for Hyena in Petticoats.

I have a few things to say about sizing the blocks.  I wanted about a 20" cushion cover, with 4 windows to stretch across each side.  I wanted to get a good number of fabrics in there, and my lovely mother-in-law (hello there!) helped me choose the right size.

Using the magic of maths (20/4, wow), that means each coloured diamond is 5" tip-to-tip (measurement X on the picture below).

No charts are necessary to help you cut your fabric when you have the power of trigonometry, my friends.  The cream fabric squares should have side 2*X once the edges have been folded in by 1/4", so you should cut squares of side (2*X + 1/2").  That means I had to cut the cream fabric into squares of side (2*5" + 1/2"), which is 10.5".  To do this, I recommend a quilter's square, a rotary cutter and a self-healing mat.  I'm linking to Jaycotts when I can because they've got a really good selection of tools, in my opinion!

To help press those 1/4" seams in, I made a 10"x10" card template.  I could then just fold the fabric around this, press with an iron, then remove the card.  Hyena in Petticoats has a good description of this method.

Each intersection of coloured windows (where the 4 corners touch) is the centre of a cream square, so I used 16 cream squares of fabric.

The coloured windows are made from squares which have side Y when the edges have been folded in by 1/4".  The magic of trig tells us that Y = X/sqroot(2), or approximately  Y = X/1.41.  Again, you need to add 1/2" when you cut out, so you can fold the edges in later.  I cut out squares of 4"x4", and folded them round a card template of 3.5"x3.5".  This cushion used 24 whole coloured squares, and 12 partial squares (missing a corner) for the edges.  The edge windows ended up with unfinished coloured bits sticking out, but they are taken care of when you attach the pillow back.

I top-stitched the curved folds because I am lazy and I don't trust my hand stitching to stand the rigours of my sofa.

I made the back from upholstery weight fabric to try and match the weight of the thick patchwork front.  When I sewed the two together, I stitched as close as possible to the edge of the patchwork piece, as there is no seam allowance on the front as such.  For a tutorial on the cushion back, clicky clicky!

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