If you repeatedly have outlines that do not line up with the design it is most likely caused by improper stabilizing and hooping. The job of stabilizing and hooping is to hold the fabric taunt and in place, without moving, in the hoop while the entire design is embroidered.
What you will need to hoop a t shirt and prepare to embroider stretchy fabric:
- The tee shirt or sweat shirt (or stretch fabric) to be machine embroidered. Be sure to preshrink the fabric before starting any embroidery process. If the fabric shrinks after you do the embroidery, it will leave a puckered embroidery design.
Press the fabric well, without stretching it as you press it. You may also want to use spray fabric sizing or spray starch to increase the stability of the fabric as you process the embroidery.
- The embroidery design set up in the embroidery machine - refer to your sewing machine manual for this aspect of preparation
- Bobbin thread in a color to match (or a close color match) the fabric being embroidered
- Decorative threads in the colors required for the embroidery design
- Temporary spray adhesive
- Stabilizer - two pieces, a bit larger than the size of the hoop you will be using. My personal preference is heat-away which turns to an ash and vanishes with the heat from an iron when you are finished embroidering. A soft stabilizer is recommended because any stabilizer that is not cut off or removed will be against skin when you are done. Water soluble stabilizer can be used but is relatively easy to end up stretching with the fabric as you try to hoop the fabric.