Working into the spiny bumps on the back of the chain creates a smooth, even edge on your project, enhancing its overall appearance. This technique also provides a sturdier foundation for subsequent rows, helping maintain the shape and structure of your piece. Additionally, it avoids the looser look that can result from working into the front loops alone, giving your finished project a polished and professional look. As a general rule of thumb, always stitch into the spiny bumps of the chain, unless specified otherwise.