Originally Posted by
Stitchnripper
Can I ask why foundations are necessary? I am only going by my own experience and my friend because we each made those 90 blocks and traded half so we would have a friendship quilt. All thin scraps - no issues. They were on the diagonal. One of my favorite quilts. What did we miss?
The foundation stabilizes the fabric to prevent stretching. Less important if you're using only quilting cottons, but a big help if you're using a variety of fabrics, and a must if you're doing a selvage quilt. Also you can use it as kind of a paper-piecing template if you want a really precise pattern.
And because I don't think anyone has mentioned it yet, you can also do the quilt-as-you-go method and use your batting as the foundation. It saves you the extra weight/thickness of a foundation fabric, and you can swap the batting for felt to go even lighter.