Universal Needles - Use for most wovens and knits. Other materials such as leather, denim, stretch, etc would be better suited for other speciality needles.
Microtex (sharp) needles - Use for micro fibers, polyester, silk, foils, artificial leather, and coated materials like waxed canvas. The very thin point creates beautiful top stitching and nice straight stitches for quilt piecing.
Twin Top Stitch - Two needles mounted onto one shank, this needle created two rows of stitches simultaneously. Perfect for creating straight lines of top stitching!
Gold Denim - Use for denim and similarly dense fabrics.