Altering inseam length on bootcut jeans - Is it tricky?

[upnorth]

I can see that this would pose no alteration problem for a straight cut but would it throw the proportions out of the window on a bootcut?

In general, are those extra 2 inches of length on a 34" inseam jeans allocated above (upper thigh) or below (calves) the knees, or equally spaced? In other words, are the knee folds still at the same position on two jeans of similar waist sizes with differing inseams?

 

[onion]

When you hem jeans the length is taken in at the hemline, hence "hemming". That means the knee will be at the same place after the alteration. The only thing you need to worry about with hemming bootcut jeans is that the bootcut can turn into a straight leg cut if you cut too much length off.

 

[NoVaguy]

I wouldn't get into speculation as to the "knee" of the jeans; what I would do is try the jeans on, see where the knee falls in the mirror, and see how the profile looks with the shortening operation (just fold the hem of the jeans). If it looks good, do it. If it doesn't, try on a different pair.