What is Seam Sealing Tape?

A Key Feature of Ready to Wear Rain Jacket and Pants

Waterproof breathable jackets and pants are considered to be top-of-the-line garments in the outdoor adventure industry. Many shell fabrics are star performers for keeping rain out while also venting excess heat and vapour, keeping the wearer more comfortable. However, the fabric alone cannot make a garment truly waterproof. Tiny holes created by the sewing needle can allow water to seep in over time or during a heavy down pour.  Fortunately, Melco Seam Sealing Tape offers an ideal solution for leaky seams!  When one looks at the seams inside a brand name raincoat, you can usually find the Melco tape quietly minding its own business hiding the seams behind its waterproof breathable tape.

Melco Seam Sealing Tape is produced by San Chemicals, Ltd in Japan and has been doing so since 1965 when they introduced the very first hot-melt seam sealing tape. Over the years, Melco tape has evolved and today there are several styles to choose from, depending upon the fabric to which it is applied. 

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What are the Benefits of Melco Brand Seam Sealing Tape

  • As leaders in the industry, San Chemicals ensures Melco tape meets Oeko Tex Standard 100 certification every year.  
  • Melco seam sealing tapes can withstand repeated washing and drying (following recommended care instructions).
  • Melco tape comes in a variety of styles to best match the performance base fabrics used in the garment.
  • Melco tape dramatically increases the waterproofness of a garment by covering the holes produced by the sewing machine during construction.
  • Melco tape is the thinnest, most flexible and most secure hot-melt tape in the market.

What Styles of Melco Seam Sealing Tape are Available?

Melco tape is available in many styles in order to match the inner face of waterproof breathable fabrics.  Typically, this includes: nylon tricot, brushed tricot, jersey, polyurethane or neoprene.


TQ-2200 Melco tape is designed for use with 3-layer laminate waterproof breathable shell fabrics such as styles of Polartec® Neoshell No Stretch or Polartec Neoshell with Stretch Ease, that have nylon tricot mesh as the backing fabric.  On our website, we have a Neoshell at a Glance chart that lists all of the styles of Neoshell we carry and groups styles by the backing fabric, making it easy to see which style numbers have a tricot back.


XTQ-2520 tape is designed for use with 3-layer laminate waterproof breathable shell fabrics with a jersey backing fabric.  There are some styles of Polartec Neoshell with a jersey back and Polartec also produces a lightweight Power Shield Pro and Windbloc (also 3-layer laminate fabrics) with jersey backs.


XF-8505 is a clear tape intended for use on 2 or 2.5-layer laminate waterproof breathable shell fabrics.  These fabrics DO NOT have a backing fabric and the tape is applied directly to the membrane material.  The HyVent DT, Aluminum Back Shell, Fab Shell and Polartec Power Shield Pro Ultralight fabrics we carry are examples of 2 or 2.5 layer laminates.


T-5000 tape can be applied to a variety of shell, softshell or neoprene fabrics making it a good choice if you will be applying the tape to multiple fabrics.  T-5000 can be used for gear, such as a kayak spray skirt made with neoprene, as well as garments.

How is Melco Seam Sealing Tape Applied?

General Tips

All Melco tape styles are designed to be applied in an industrial setting with a commercial grade welding machine.  However, San Chemicals advises that these tapes may be applied at home using a mini iron however, the weld will not have the same extremely high bonding rate that it does when applied with industrial equipment.  

DISCLAIMER:  Neither San Chemicals nor Discovery Fabrics accept any responsibility on the outcome of your project using Seam Sealing Tape.  This article is for information purposes only. Any time you are working with heat there is a risk, and you must assume that risk.  

It is ALWAYS advisable to test your tape application on scraps of your fabric prior to tackling your main project.  Use a pressing cloth or parchment paper over the tape and seam as high heat is involved and this will help to protect your tape and fabric.  Heat can damage fabric, so be sure your iron will not damage your fabric by testing on inconspicuous areas or on scraps of the fabric you intend to seal. 

When testing, be sure to find the setting that provides a good bond.  It is NOT advisable to apply Melco Tape with a regular home iron as the heat plate is simply too large and could damage your garment.  

Melco Seam Seal Tape Application Steps

  • after completing your seam, run a second line of stitching close to it, within your seam allowance to stabilize seam prior to taping
Photo of a seam of double stitching ready to be trimmed

  • trim off excess seam allowance close to the second line of stitching as this keeps bulk under the Melco seam seal tape to a minimum and ensures more area for the tape to adhere to the main fabric
Photo of a seam of double stitching after the seam allowance has been trimmed
  • fold the trimmed seam over and lay the tape so it is centered over the cut edge of your seam
  • place parchment paper or a pressing cloth over the Melco tape and fabric and slowly run your mini iron over the tape at the settings determined in your testing. Check you seam as you go to ensure a good bond is achieved. After the tape cools, test the bond and repeat if necessary.

Photo showing placement of Melco Tape over a seam ready to be welded with a Clover Iron

  • Melco Seam Seal Tape after ironing with a Clover Mini Iron
Melco tape successfully applied to seal a seam

How to Remove Seam Sealing Tape

  • You can also REMOVE Melco tape with a mini iron. This trick is handy if the tape on your ready-to-wear jacket or pants is losing its bond and you wish to apply new tape. Simply heat sections of tape as described above (be sure to use a pressing cloth or parchment paper!) Carefully peel back old tape as you go.

Where Can I Buy Seam Sealing Tape?

Discovery Fabrics has an assortment of Seam Sealing Tape by Melco.  We have tried other brands and have found Melco to be the best. It is the one used by most high quality outerwear manufacturers.