Zig 2 way has a 3mm tip. This color changing glue can be used in two different ways: When the glue is wet (blue) the bond will be permanent. If you let the glue dry it will be a temporary bond which leaves no residue. ZIG 2 Way Glue Pens are ideal for making items repositionable, great for adhering glitter to cards and scrap book pages. ZIG Glue Pens are Acid and Xylene free.