Envelope Pillow Cover Tutorial
You will need:
pillow form
fabric (see Step 1 for amount)
measuring tape
sewing machine

Step 1: Use the measuring tape to measure your pillow from side to side and top to bottom. Mine is square and measures 19″x19″. Don’t pull the measuring tape too tightly, just keep it snug.  You will add 1″ to these measurements for your larger piece. You two smaller pieces will be the same length and then the length minus 6″.  So for my pillow, the large piece is 20″x20″ (because I add 1″ to the 19″x19″) and then the two smaller ones are 20″x14″ (subtracted the 6″).

Step 2: Place your fabric right side down.  If you have a 10 week old kitten who is insanely curious, ignore him. Use the measuring tape and marker to measure your large piece. As I said in Step 1, mine is 20″x20″.

Step 3: Measure your two smaller pieces. Mine are 20×14. Again, ignore the kitten.

Step 4: Go lock kitten in bedroom because he was trying to eat the pins. Lay your large piece down right side up. Lay the two smaller pieces on top, right side down, so that they are lined up with the big piece on both short ends and one long end. Pin your sides (the long side of the smaller pieces) about 1.5″ in from the edge. A trick with pinning is to put your pins pointy end pointing down on your right side and pointing up on your left side.

the two smaller pieces will overlap in the center

 Step 5:  Sew along the edges you pinned. You will be using a 1″ seam allowance for this project.

Step 6:  Lay your fabric down completely flat (pull the side panels out so that they are flat too), wrong side facing up. Fold in your edges around 3/4″ and use the iron to press them very flat. If you have matching thread and can sew a neat, straight line then you can sew down these folded edges. I chose to leave mine, I just ironed them. Upside to sewing is that they will not lose shape if washed. If you only iron, you will have to re-iron it later after washing.

Step 7:  Lay the fabric wrong side up and press the inside seams flat.
Step 8:  Flip your fabric over so it’s right side up. Fold your panels/smaller pieces back onto the large piece and pin them like you did in the beginning but this time you will be sewing the other two ends. Sew the ends, again with a 1/2″ seam allowance. Now all four sides should be sewn. 
the panels/smaller pieces should overlap in the middle still
Step 9: Cut off the corners, just the fabric don’t cut the stitching!

Step 10: Flip your pillow cover inside out so that the right side is showing. Stuff your pillow in through the envelop opening and you’re finished!

 I have made three of these now. The two larger ones are the same size (from Ikea) but over time the yellow pillow really deflated! I will probably take the cover off and sew it smaller. For the pillow in this tutorial, I purposely made it a bit smaller because I knew this would happen.

All three fabrics are from Jo-anne Fabric and Craft Store.