Banners have several terms like scrim, denier, and ounce that you may not understand. Scrim vinyl is the most common substrate for printing outdoor banners. Scrim vinyl is a polyethylene substrate, reinforced with polyester cording. This internal cording is what gives it strength and durability to withstand damaging winds and weather conditions. The smooth surface makes it a great contender for displaying graphics and text. Denier is a term used to measure textiles and scrim banner, specifically to measure the thickness of threads. A 500 denier thread means that the single thread has been twisted 500 times in the finished length of 1 inch. The higher the number the thicker and stronger the tread. Denier is a primary driver of the price of the material. Ounce refers the weight of one square yard of material, 10 oz or lighter usually should only be used indoors or for protected outdoor use, 13 oz can be used outdoors and 18 oz for long-term outdoor display.
Here at Pinnacle Signs and Graphics we use 13 oz 9×9 scrim, 1000×1000 denier material for our banners unless the intended use requires a heavier material. Our banners always come with hems and grommets unless the customer requests them left out. Very few banner manufacturers offer a durability warranty for their banner material because of the extreme range of environments banners can be placed in. Durability of any banner material is determined by how and where it is installed, how long it is displayed, as well as the temperature, humidity, wind, and sun it is exposed to. While customers can control how a banner is installed, and how long it is up, no one can control the weather. Generally, a 13 oz banner could last up to 1 year in continuous use outdoors provided it is installed properly.
Installation: Should you install with Bungees or Rope – The correct answer is both. Banners should be strung up on the top and bottom with good quality rope. The banner should be taught, with no excess to flap loose in the wind. In addition, the corners of the banner should be pulled taught with bungee cords. This allows for the banner to flex with the wind, and still stay taught when the wind calms. Wind – It is a fact that no matter how well a banner is fabricated, it will not sustain prolonged or excessive winds.
Other best practices: Never cut wind slits into the face of a banner. The idea is that the flap of material will allow the wind to pass through and take the strain off the hems and corners. The reality is that cutting slits cuts the mesh scrim that makes the banner strong. If the edges of the banner are properly hemmed and supported, they will be strong enough on their own with proper installation.
Hems are important for a number of reasons. First, folding over the edge of the banner to at least 1” or 1 ½” will provide the reinforcement that the banner needs around the edges to take the pressure from regular day-to-day winds. Doing a double fold offers additional strength for tougher conditions. Second, hems provide a strong foundation to properly support anchor grommets. Grommets placed close to an un-hemmed raw edge will tear out with minimal stress. All four edges of the banner should be hemmed for optimal durability.
Stitching vs. Taping – There is little difference to durability if a banner hem is made by using special double-sided tape versus sewing. Just as the banner tape should be good quality, so should the thread used. One detail on sewing the hem – do not exceed 5 stitches per inch or there is risk of perforating the banner and weakening it.
Grommets – Metal rings placed through the face of the banner near the edge (and on a hem) give the proper strength for hanging up the finished banner. Grommets should be placed at least ¼” in from the edge of the banner and spaced every 24”. If a banner is very large or expected to be subject to harsh conditions, consider placing grommets every 12”.