Corrugated board is one of the most versatile packaging materials available. It can be adapted to fit almost any shape and protect a wide range of products, from small, fragile items to large, heavy items. It can be manufactured with high crush resistance, high-quality printing, or a low profile to reduce storage. Thinner corrugated board can be used as an alternative to folding cartons to add protective cushioning to fragile items without sacrificing print quality. The arc-shaped flutes are one of the reasons corrugated packaging is so versatile. 

The Role of Flutes 

Single wall corrugated is comprised of two sheets of linerboard interleaved with one corrugated medium (flutes). Stronger double and triple wall corrugated have additional layers of flutes and linerboards interweaved. Double wall has three linerboards and two corrugated mediums, and triple wall has four linerboards and three corrugated mediums. Double and triple wall corrugated boards may use a variation of flute sizes used depending on the application.  

The flutes provide strength and cushioning for the box. The flutes form rigid arches, and when combined with the linerboard and adhesive, they are capable of sustaining a lot of weight when applied perpendicular to the columns. The space within the flutes adds a layer of cushioning protection. Larger flutes provide greater strength, and small flutes have better printability and foldability. 

In recent years there has been an increase in the number of flute profiles available, and the flute measurements can vary from manufacturer to manufacturer.  The five most common flute types are: A, B, C, E, and F.  The letter designation was assigned based on the order they were created and not the flute size, which can be confusing when trying to figure out which you need. 

  •  A flute was the original flute profile and has about 33 flutes per foot. 
  • B flute was developed for canned goods, which wouldn’t require boxes that supported much load. It has 47 flutes per foot 
  • C flute was developed as an all-purpose flute with about 38 flutes per foot. 
  • E flute was developed next and has about 90 flutes per foot 
  • F flute was developed for small folding cartons and has 125 flutes per box 

E Flutes and F Flutes as Alternatives to Folding Cartons 

E-flute has on average 90 flutes per foot, and F-flute has on average 125, making them both an ideal choice for high-quality direct-print or litho-laminated graphics. Both are an eco-friendly replacement to folding cartons – sometimes called paperboard boxes or chipboard boxes.  

Folding cartons are intended to hold products and provide a surface to showcase graphics; however, they offer little protection. Fragile products such as cosmetics, glass, ceramics, and other delicate products need additional protection without having additional weight, and this is where E flutes shine. The thinness of these mini flutes allows them to provide strength while reducing the fibers used.  

However, F flute is very thin – only about 1/32 in. It is often used as clamshell packaging for fast-food restaurants and is very much a niche product. If you’ve gotten your cheeseburger in one, you will understand it’s not going to provide much protection. E flute, is the most used micro flute and is readily available vs the niche of F flute. It is still thin at 1/16 inch but has superior crush resistance and a flat surface. These characteristics – thin profile, cushioning properties, and flat surface – make E flute an excellent alternative for conventional folding cartons when you need lightweight packaging, protection, and an excellent printing surface. 

When you use E flute as an alternative to folding cartons, you don’t have to sacrifice luxury. For premium printing quality, a coated white liner can be used that allows a shiny finish using direct print, and because it is white, colors appear more vibrant.  

Progress Container Your Packaging Partner 

Not sure which is best for your project. Progress can help. We were one of the first in the industry to have an in-house structural design department, and our team has more than 75 years of combined experience. No matter what your packaging challenge is, we have the knowledge and capabilities to create packaging that will not only protect but will get noticed. Contact us to get started.