Sewing with delicate fabrics: Guess the tool!

Dear Readers, I promised you on my Facebook Page that June will be a month of sheers or delicate fabrics on my blog (partly because my next Burdastyle Couture project will be made with delicate fabrics).

And, in this first post I am asking you to guess what's the tool on the photograph below (it's related to sheers, I promise!):

The best answer will be featured in the follow up post, and I will be more than happy to promote any sewing related link included in that comment! Your turn now!