The Problem of Pants, Part Two...

...that is to say, I've got the list of four main differences between store-bought jeans and pants based on sewing patterns. Here it is.

1) Tight fit

I'll start with a rather obvious point, and state what seems to be the general philosophy of jeans makers: "Why bother with properly fitting pants when we can just force your legs into overly tight jeans?". I mean really, how many (offensive) dieting commercials have you seen where the girl struggles to fit herself into a pair of jeans? All she's doing there is forcing her lower body fat into a denim mould--the jeans aren't fitting around her, she's fitting herself into them.

But while this might work fine for commercially-manufactured jeans, it clearly doesn't work for pattern-based pants, since by definition those try to take actual fitting into account. However, a pair of pattern-based pants usually can't act as a tight-fitting mould for another reason.

2) Spandex and heavy fabric

Part of the reason jeans make, as I said, the perfect mould, is because of the composition and weight of their fabric. The standard 3% spandex to 97% denim ratio ensures that the pants can be tight without being overly uncomfortable. As well, the denim is usually heavy enough that it can keep its shape even when the fit is imperfect, instead of being distorted by unexpected curves or planes.

However, most suiting fabrics sold at fabric stores (cotton twills, linens, and even denims) are lighter than those used in ready-to-wear jeans, and don't necessarily contain any amount of spandex. This lack of elasticity means the pants can't be as tight-fitting; it also means that no matter how loose the pants, there's less room for leeway when sewing, and as a result, usually less room for comfortable movement when the pants are worn.

3) The crotch curve

When it comes to comfortable fit and movement, the curve of the crotch seam (the seam that joins the two legs) is easily the most important aspect of fitting the pants. It'll be simpler to just show the difference between the crotch curve as found on store-bought jeans, and the curve on home-sewing patterns, before I explain why and how these curves change the fit.

Crotch curve of jeans               Crotch curve of pattern

The jeans have a deep and even exaggerated crotch curve, which follows the actual curves of the stomach and hips. On the other hand, the shallow dip along the crotch curve of the home-sewing pattern means that the seat of the pants will likely be too close-fitting. As well, the back crotch section on the jeans has a convex curve near the top (the area in red), which means that the pants will adhere properly to the concavity at the small of the back. On the sewing pattern, the straight edge along the top of the back crotch curve (also in red) means that the pants will instead leave a gap between skin and cloth.

Front crotch curve on both jeans and pattern

The lack of curving along the top of the front crotch curve on the sewing pattern also means that it doesn't take the possibility of a rounded stomach into account (which, really, it probably should). It's true that the jeans aren't curved along the top of the front crotch section either, but points (1) and (2) (that is, the tight mould-like fit and fabric composition) make that curve mostly unnecessary.

Jeans inseam

 4) The inseam curve and the sewing along the crotch seam

The issue with the inseam curves is mostly the same as the issue of the crotch curve. The storebought pants have an inseam which has a sharp curve at the very top, whereas the sewing pattern's inseam has a longer, shallower curve. This means that the jeans will start following the curve of the inner thigh higher up on the pants leg, which obviously leads to better fit.

Trousers inseam

As well, the actual crotch seam is sewn differently in jeans, when compared to normal trousers. Topstitching along the crotch seam of jeans forces the two legs to automatically curve smoothly away from each other and then down. The trousers are sewn with a normal reinforced seam, which allows the two legs to simply hang down on either side of the crotch seam, instead of automatically following the shape of the actual crotch and legs.


Of course, while these four points differentiate jeans from homesewing patterns, they can also be used to improve the fit of pants that are based on those patterns. The crotch and seam curves can be adjusted directly on the pattern tissue, and the problem of fabric composition can be solved before even starting the sewing process. I'm actually starting on a third pair of pants this week, and I'm adjusting my drawings based on what I've learned about the fit of jeans. Hopefully they'll turn out better fitted than my previous pairs.