Step 1: Measure the pillow form
Measure your pillow form with a measuring tape, from seam to seam.
Tip: If either of the fabrics you’re working with are wrinkled, give them a quick iron before you begin.
Step 2: Cut fabric for front panel
To figure out the dimensions of your front panel, add 2 in. / 5 cm. to the width and height of your pillow form measurement. Cut this measurement from the fabric you wish to use for the front of your pillow. (We used a 12 in. x 12 in. / 30 cm. x 30 cm. square pillow form, so we cut a 14 in. x 14 in. / 35 cm. x 35 cm. front panel)
Step 3: Cut fabric for back panel
To figure out the dimensions of your back envelope piece, add 6 in. / 15 cm. to the width of your pillow form measurement and 2 in. / 5 cm. to the height. Cut this measurement from the fabric you wish to use for the (We used a 12 in. x 12 in. / 30 cm. x 30 cm. square pillow form, so we cut a 14 in. x 18 in. / 35 cm. x 45 cm. back panel)
Step 4: Fold and cut
Take the back piece and fold it in half. Cut along the fold.
Step 5: Prepare to hem edges
Create a ¼ in. / 6 mm. fold around the long edge of each of your back pieces. Fold again, pin, and sew. These pieces will be the opening of the back of your pillow case; hemming them will make the opening look neat and finished.
Step 6: Line up fabric pieces and pin
Once you’ve hemmed both pieces, take your square piece and put it pretty-side up. Take your smaller rectangle pieces put them on top of your square piece, so they’re lined up with the square piece (they'll overlap each other). The seam on the envelope pieces should be facing out. Pin all sides together, including the overlapping pieces.
Step 7: Sew edges
Sew around all edges, leaving a ¾ in. / 2 cm. seam allowance.
Step 8: Trim excess
Trim excess fabric from the sides, leaving a ¼ in. / 6 mm. seam allowance.
Trim corners at a 45 degree angle, being careful not to cut through your stitching. This will help with the way the corners lay when flipped right-side out.
Step 9: Flip right-side out
Flip right-side out and put over your pillow form.