Silver filled head pins provide you with a great alternative to sterling silver head pins. All of our silver filled jewelry findings are comprised of at least 1/20th silver by weight, giving you a surface layer of silver that is hundreds of times thicker than a plating. Sometimes called silver overlay, silver fill is created by using heat and pressure to apply a thick layer of either .925 sterling silver or .999 fine silver to a base of less costly metal. Like solid silver, silver fill will oxidize over time.