In my world of hard to break habits lies the mysterious world of ironing.
To explain I mean I have a tendency to want to iron my fabric, my seams, and my finished blocks instead of pressing them.
This is what happens when you iron a seam instead of pressing it.
Because I forgot to press my seams (I ironed instead) I stretched out my fabrics. When I sewed the block together I noticed that I had created what are called pin tucks. Pin tucks happen when you stretch fabric to make it match another piece. It's very tempting to stretch block pieces so they'll fit perfectly but resist!
One stretched seam amplifies itself many times over, ironing will aggravate it even more.
What's the difference?
When you iron something, anything really, you're essentially pulling and stretching the fibers of the fabric with a hot and somewhat heavy piece of metal. You're attempting to physically, and hopefully gently, stretch out any wrinkles in said fibers.
When you press something you are attempting to create a "wrinkle" or a seam in your fabric. Pressing also, as the word implies, does not involve pushing, pulling or stretching fibers. Permanent pressing involves lots of steam to "set" the seam.
When you're piecing together a quilt block you'll often see that the directions will tell you to PRESS open a seam or to PRESS a seam in one direction or towards another seam. Pressing and ironing are two different methods and should never be treated as the same thing.