I am going to make an electronic template outline for a cover for the Ikea V-shaped pillow, then fill the outline with my decorative pattern, then print it onto fabric. Just printing the actual shape that I need will save a lot of ink, plus some fabric too, and will give me a better fitting pillow cover.
I am drawing my template in Adobe Illustrator. First of all I lay my pillow on the floor and pull it into shape. It is essentially two thick sides of a square, with the inner and outer corner joins having been curved.
Using a tape measure and measuring from seam to seam over the curved, filled, pillow, I can see that:
Side A is 80cm Side B is 80cm Side C is 35cm Side D is 35cm
I will have a 1cm seam allowance on each side.
In Illustrator I draw vertical line A (holding down shift while I draw a line tool to make the line straight) 82cm long. Then starting at the top of that line I draw horizontal line B, 82cm long.
Tip: The length of the line can be adjusted once you have drawn it: select the line with the hollow pointing arrow/selection tool, then type in the precise width or height you want for that line in the boxes that appear under the menu at the top of the screen. Or, once you have some lines in place, you can click and drag the blob at either end of the line to resize it to meet some other point.
Starting at the unjoined end of line A I draw 37cm wide horizontal line, C. Starting at the unjoined end of line B I draw 37cm tall vertical ine, D.
Starting at the unjoined end of line C I draw vertical line E, which goes up to meet line A. Starting at the unjoined end of line D I draw a horizontal line F, which goes across to join line B. Now my template looks like this:
Using the tape measure I ascertain that the inner curve starts 37cm (38cm including the seam allowance) up from the intersection of lines C and E, a point that I will refer to as CE, and ends 37cm (38cm including the seam allowance) across from the intersection of lines D and F, a point that I will refer to as DF.
To draw the outer curve, I select the Illustrator Arc tool (another option under the Line Tool button), click point AF and drag to point BE.
To draw the inner curve, using the Illustrator Arc tool again, click point CE and drag to point DF.
My template in Illustrator currently looks like this:
I drag the appropriate end points of lines A, B, E and F in turn so that there are no extraneous lines on the inside or outside of my template. It is also important that all the lines join: there should be no gaps in the template or when we fill it with pattern, the pattern will leak out.
Now my template looks like this:
I "select all" in Illustrator, and copy. I open a new file in Photoshop and paste my template into it. I select the paint bucket tool, and fill my template with a pattern.
Next, print the template twice, then cut out and sew the two pieces together.