So I've been wanting to do this ever since Google honoured the inventor of the zip a couple of months ago! After all, where would we be without this nifty little invention eh?!
Start off with a base coat colour and paint your entire nail apart from a small triangle at the base. Secondly, using a silver paint on a blob at the top of your nail as the zipper end. Then at the opposite end, paint a small triangular blob. Once these are dry, paint on the zip detail - painting small horizontal lines back to back. Again wait for this to dry! Then paint another silver blob at the top of the zip in a sort of pear-shape, leaving a small hole. Finally, use a black nail art pen for the zip detail! All done!
Hope you like it!