By Jeffrey the Barak.

Online shopping is amazing. It is so convenient and usually a great bargain too as sellers don’t have the enormous cost of providing a glass and granite palace to show you their goods.

But some things do not fit in with the online shopping model. The most striking example is denim jeans. Jeans that fit well look great on anyone, but jeans that are the wrong size or shape look awful. Besides there being so many choices of fashion, shape, narrowness and fabric in today’s jeans, the size labeling is only loosely based on reality.

Let’s take mens Levis jeans as an example. In the world of mens jeans, there are Levis, and then there is everything else. If your jeans are not Levis, then it could be said that they are homages to Levis. Levis are the standard in mens jeans and every other brand, be it $12 in Ross or $500 on Rodeo Drive are just variations of proper Levis.

Now the average guy does not get into shopping as much as the average lady. Mister Average wants to know what waist size to ask for, throw the first pair into a basket and check out. But the odds of that working are pretty slim when it comes to jeans shopping.

In the case of Levis, there are different cuts or styles made from different patterns, ranging from super skinny to baggy. And if you decide on just one design, for example, the current best selling 514 Straight fit, which used to be called 514 Slim Straight and may be getting replaced by 513 Slim Straight, and then you pick up, for example size 34 waist and 30 leg, and take one in each fabric choice to the fitting room, you will find that each color is a very different size, and some are made in China, some in Mexico, some in Egypt etc.

Some of the fabrics are heavy and do not have any stretch, and they might impart a big indigo stain onto any damp fabric that touches them. Others are medium-weight with the ability to stretch, or not, and others are light, and not necessarily stretchable. There are dozens of different types of denim in jeans that have Levis labels on them.

Say you want skinny jeans, how do you know if your legs and butt will look better in 511 Slim which used to be called 511 Skinny or 510 Skinny which used to be called 510 Super Skinny? How will you know if they hug your hips and stay up, or if they will be sliding down and giving you a baggy crotch and short-looking legs, and how do you know if the iconic Levis back pockets will be sewn on high to align with and flatter your buttocks, or be half way down to your thighs making you look long-torsoed and short-legged?

And if you buy button-fly 501s, like you did in the fifties, sixties, seventies, eighties, nineties and naughties, will they be the same as before, or do the pockets move up and down and grow and shrink in size, and does the waistband rise and fall over the years, and do the thighs get tighter and looser? In other words does the pattern change despite the pants having the 501 label since your grandfather wore them? Well yes, 501s across the years are very different from each other, and Levis make no announcements when they introduce the newest major change in the design of 501s.

So we cannot rely on a certain style, such as 501, 505 or 514 being the same from pair to pair, and we cannot rely on a certain size being consistent over two different colors in the same style number, and we cannot rely on the fabric’s weight and stretchability being consistent from color to color. How then can we buy online and expect to be able to get jeans that fit?

Well we cannot. The world’s most fantastic store, Amazon, may also be the worst place to buy jeans. You really have to physically visit a place that has a large inventory, such as JC Penney, Sears, Macy’s or The Levis Store, and then you have to take your time, trying on various style numbers, in various fabrics and various waist and leg measurements.

You may find a good pair in a few minutes, or you may have to work at it, changing pants many times and allowing the hour hand to swing around the clock. And it will be worth it, because the difference between well fitting, figure flattering jeans and jeans that you can just get on is a huge difference.

Depending on the shape of your body, you will see that your legs have to be a certain width, your back pockets have to be a certain height, size and distance apart, and your fabric has to be a certain wash to make you look your best. It is more complicated than choosing a new car or a new smartphone. And if you look good you feel good. If you don’t like how your jeans make you look, it will affect how you feel and behave. That is how important this is. When your butt looks sexy you just feel better.

But even this level of caution may not be enough, because each type of fabric behaves differently when it is first washed. So you may find the right inseam length, but depending on which denim it is, it might stay the same length, or it may shrink a bit. This aspect may be out of your control so try to buy jeans at a place that accepts returns, then wash them, in cold water with mild soap or no soap, all by themselves with nothing else in the machine, and hang to dry. If they do shrink, take them back with your labels and receipt and exchange them for some in the identical fabric with a longer inseam. And then do the same test wash on those.

And if you find after all this that you have a perfect pair, then you can risk buying a second pair online, the same style, the identical fabric and color, and the same waist and leg size. It may end up being the same, or it may be from an entirely different pattern and made in another country, and you may have to kick yourself for not just going back to the same store and trying them on.

So why then, if there is such terrible inconsistency, do people still overwhelmingly choose Levis? Well lets put it this way, some designer jeans look positively silly, embarrassingly so, and we want to look cool, not silly. And even though the guys with the beer bellies, digging the ditch outside the store also have Levis on and they don’t fit very well, we still look our best when we find that perfect pair. That red tag, that leather patch, those rivets, that pocket stitching. These details represent iconic classic American style that you just don’t get with those New Hampshire Sunsiders, or those Western Grease Limiteds, or those Carlo Pininfarinas.

Writer Jeffrey the Barak hides black jeans inside old oil cans and then fires them at squirrels using a giant catapult, every Wednesday at 3 AM