Let's start with a definition of ease: the difference between your body measurements and your apparel measurements, usually and particularly the width of the body or sleeves.
Ease determines the extra room you need to move. Remember in high school when you wore those skin-tight jeans that left marks at your waist? Or maybe that's just me. I could have used a little ease back in the day. Now I'm grateful for the lycra they put in mom jeans. I get all the comfort I need to accommodate lumpiness and eliminate bagginess. Best of all, no uncomfortable zippers either! Thank God for elastic waistlines. (I'm sure three-quarters of the female population would cringe at this proclamation, but I don't care. It's my truth.)
Ease also determines the room you have to layer garments. For example, if you want to wear a T-shirt under a sweater, you don't need a lot of ease. But if you're going to wear a coat over a bulky sweater, you want lots of ease. We all remember poor Randy from "A Christmas Story." (I just spied his cool mittens - I'd love to make a pair of those.)
Speaking of bagginess, it is also related to ease. While we may love wearing a big sweatshirt on a blustry day, it's probably not our most becoming look. But if we're laying around the house, we really don't care, do we?
So what does this all mean for knitting? The Craft Yarn Council defines ease as follows:
Let's talk a moment about negative ease. Designers often make sweaters with zero ease or even negative ease if they want the garment to be very form fitting. One example: the Peyton Cardigan by Connie Chang Chinchio. This sweater just wouldn't work without negative ease; the gaping at the front openings is integral to the design.
Pullovers also come with negative ease. One example: Ysolda's Snow White. She looks lovely in this design, doesn't she?
Negative ease for larger figures often breaks down along generational lines, I suspect. Younger women, regardless of size, wear much more revealing clothing now than in the past. As an example, look at this dress from Forever 21. Even when I was thinner, even when I was younger, I wouldn't have worn something this fitting or short. I just wouldn't. But most young women seem to be comfortable with this look and good for them.
Maybe it's because I'm old, but I want positive ease and I believe it's important for larger figures. I've long suspected that ease on a skinny gal works differently than ease on an ample one. If we were talking about height instead of weight, an extra few inches would make a big difference between a tall and a petite woman, right? Wouldn't the same be true for wider women?
My bottom line? My bottom needs more ease than a thin woman's. My knitting friend, Dottie once suggested that ease should expand proportionally as the sweater increases. She's right! Let me give you a real-world example.
Assume a designer creates a sweater pattern for a 36-inch bust with two inches of ease for a finished bust size of 38 inches. If we divide the ease by the finished bust size, we discover that ease is 6% (2 / 38 = .06 or 6%).
Now, let's assume I want to make this sweater for my 56-inch bust. The problem is, if I only add two inches, it means I'm only adding 4% of ease, as shown in this little spreadsheet.
What I really need to do is add at least 6% ease to my 56-inch bust size - or 3.5 inches, not just 2 inches. The additional ease assures that my sweater fits the same as the smaller version. Makes sense - if you can get past the math anyway. :-)
But I still wonder if ample women need even more ease - or at least different ease. Perhaps the bodice should only have two inches of ease, but the hips (or my hips anyway) should have six? I suspect this would work better for me, but I don't have any empirical evidence other than that my last sweater, the Under Toad, has this ease and it fits me really well.
So, I'm still worrying about ease. I'll keep experimenting and cogitating and will share the results of my research when I have more to report.