This post is dedicated to Mrs. Linda, you have my apologies for not having this information front and center! For the Mylar Bags we sell at Advice and Beans (Discount Mylar Bags), there are a number of ways to seal them, including with a straightening iron, some vacuum sealers, and a hot jaw sealer. As most everyone probably has a clothes iron around, here are instructions for using one to seal Mylar.
1. Place the bag on a flat surface. The two sides of the open end of the bag must be flat and without wrinkles.
2. Set the iron to “wool.” The wool setting will be warm enough to seal most Mylar bags. Thicker bags may require a higher setting. You do not need to place a cloth or anything in between the iron and the surface of the bag. IMPORTANT: The material of our bags has been designed with a heat resistant outer layer. We accept no responsibility in attempting to do this with other packaging materials. Please note you can melt even the outer layer if your iron is set too high or you keep the heat on the bag for too long.
3. Seal the bag closed with the iron. Go over the bag several times in a three to four inch wide band creating a wide seal area. Watch closely for even small wrinkles. A small wrinkle in the seal can remove 95+% of the barrier proprieties of the bag.
For more info please see the following YouTube video. (This is #1 in a 3 part series; you can link to the other parts from YouTube)