You've made up your mind. With a few easy projects under your belt, it's time to step up to the big leagues and make your first piece of down gear. Maybe it's a quilt, or perhaps a beanie. Regardless of what it is, your first piece of down gear is DIY graduation day. You don't want to fall on your face after grabbing hold of the diploma.
That being said, one of the key decisions in preparation for your first down project (or down-like synthetic e.g. Primaloft) is fabric selection. It makes sense that you need a "downproof" fabric, but what does downproof mean and how do you select a fabric that won't leave you covered in feathers? It just so happens that we asked ourselves these same questions when developing our first downproof fabrics. Here's what we found out.
To start, "downproof" is a misnomer. In much the same way as "bulletproof" vests don't stop every bullet, all fabrics labeled downproof, even the best ones, will leak some amount of down over time. The trick is to find the ones that leak the least while also offering breathability and/or water-resistance. In our experience, creating a downproof fabric can be broken down into three factors: weave, density, and finishing. Let's look at those in a little more detail.
1) Weave - This is the technique in which the individual yarns are interlaced to form the fabric or cloth. There are a number of different weave types - twill, satin, ripstop, plain, etc. Each weave type results in a fabric with different properties and thus pros/cons for particular applications. In our experience, when it comes to making a downproof fabric, the PLAIN/TAFFETA weave has always resulted in the better performing fabric. This started as simply an observation from field use, but is also backed up by our testing of ripstop vs taffeta fabrics through the International Down and Feather Labs or IDFL. This doesn't mean that ripstop weaves can't make great downproof fabrics. They can and do in some cases. Specifically, we've found a plain weave to be essential for downproofing in very light/thin fabrics such as 15D or 10D.
2) Density - By density we are referring to the tightness of the weave and how closely packed the individual yarns are. This is important for obvious reasons. If there are fewer "holes" in the weave, there are less places for the down fiber to escape. With all else being equal (denier, yarn, weave type, etc), a denser weave will result in a fabric with better downproofing.
3) Finishing - Lastly we have finishing. This is the last step in the fabric production process where specific steps are taken to alter the fabric in some way. One of the most important steps for the ultimate downproof properties of any given fabric is the calendering process. In a standard calendering process, the fabric is ran through heavy, heated rollers or drums that flatten the fabric and effectively "seal" the weave. Visually this results in a fabric with one shiny side and one matte side. The basic process of calendering is shown in the video below:
Although every downproof fabric is calendered, it is VERY important to point out that not every calendered fabric is downproof. This is an important point that is missed quite often by both consumers and vendors alike. Moreover, the specific techniques employed in the general calendering process can result in everything from a mediocre downproof fabric to an EXCELLENT downproof fabric.
So now that you know what goes into creating a great downproof fabric, how do you make your ultimate decision? Truth is, an excellent downproof fabric depends on an optimum combination of not only weave, density, and finishing techniques, but other variables such as yarn type and construction as well. How do you sift through the technical stuff and just get the best fabric for your project? At the end of the day, there are two questions we feel you should ask when selecting a downproof fabric:
1) Has it been lab tested? In effect, this means "Has it been tested by IDFL?". This is the industry standards organization for down and feather testing and they specialize in testing materials for down leakage. If the answer is YES, you should look for a score of 4 or 5 stars on any fabric you're considering.
2) Has it been field tested? This is where the rubber meets the road. If you're making a down quilt, are there other down quilts being used out in the field with this fabric? How has the fabric held up for down leakage with normal use over time? Lab performance is often a great indicator of ultimate field performance, but the bottom line is determined by how well the item holds up for down leakage in the field.
So that's it. Our two cents. When it comes to your first DIY down project, is it worth risking such a large amount of time, effort, and money on a fabric that can't stand tall and answer these two questions? At Ripstop by the Roll, we've made it a priority to test ALL of our listed downproof fabrics through IDFL labs. You can find the IDFL test results/status listed on any given product page. In addition to requiring a 4 or 5 star rating for lab testing, we also collaborate with some of the best down gear makers in the business such as UGQ Outdoor Equipment for field testing and end use of our fabrics in their products. We do these things not because we have to, but because we WANT to. Gaining your business is a privilege that we don't take lightly. We want nothing more than to supply you with the best possible fabric at the best prices now and in the future. So in a word...
Owner, Ripstop by the Roll LLC