spiveyt2

dibs on the SDs

Thank you both for answering that question. I had no idea that indigo was yellow in a reductive state. Now, back to wild_whiskey's thoughts earlier on dipping times with jeans, since oxidation is merely a process that turns indigo into the desired color, the time taken in between dip times is more of an evaporative process than an oxidative one? What I mean by that is, according to w_w's experience with a lack of color deepening after 6 dips, it is more a matter of water/other elements evaporating from the denim after a certain time that allows for more indigo to be absorbed into the fabric to increase depth of color after 6 dips? I guess what I am trying to get at is a question I tried to ask in another thread was that at what point does more dipping cease to make a difference. I am sure that this differs based on weight of fabric and other absorbtion properties. I am just skeptical with the marketing of jeans as having "x" amount of dips necessarily being better based on a higher number.

Wow. L.A.Gear, Bugle Boy and Gloria Vanderbilt? When was that last time anyone saw those?

There have been a number of remarks as to indigo oxidizing but what exactly happens to it when it does oxidize? I am not speaking chemically, I just want to know what the difference is to the eye. Does it turn a lighter blue, some other color, or what?

If I am remembering correctly from other posts, I thought the wearing in time was more affected by the dyeing process (how many dips/what other impurities are added to the synthetic vs. pure synthetic indigo/where the natural indigo was grown and how it was extracted) that determined the difficulty of breaking in. Though I am sure that there would probably be a connnection between the care involved (a lot) with denim producers who use natural indigo versus those who use synthetic indigo (i.e. all massed produced jeans) which would lead to longer fading times. Could be wrong.

where do you find these pics?

depends on the pair. anywhere from 1 lb. 4 oz. to almost 2 lbs.

Edited by spiveyt2 on May 8, 2006 at 10:14 PM

Thank you for your very informative posts. I do have a couple more questions, though. 1) So, with the more extensive dyeing process, I assume that it would take longer to break in Japanese denim and would require more wear to show contrast due to the indigo being more tenacious. I guess what I am getting at is that for there to be high contrast, there has to be a simultaneous leakage of indigo in stressed areas and retention of indigo in unstressed areas. These seem to be contradictory elements. How can denim simultaneously leak indiog quickly and retain it well? I apologize if I am repeating myself or beating a dead horse (though, I know by reading lots of posts that none of you are strangers to answering old or redundant questions). 2) Is there a point of diminishing returns for dipping fabric in indigo? In other words, how much different is the color from dip 25 to dip 26 in your high dip example? I am sure there is a finite amount of indigo that fabric can absorb before it stops taking in dye. I just wonder if a lot of companies don't do as many dippings not just because of time and cost but because there is little improvement. Take vodka for example, it is the trend these days to say that you distill the product an absurd amount of time when it rarely makes much difference after, say, the seventh distillation. Eventually, there just aren't enough impurities to remove for it to make a detectable difference. Thank you for your patience for a curious n00b.

Quote:

Quote: I would assume that the two are molecularly identical (or are they not entirely?) and should produce identical results.

--- Original message by spiveyt2 on May 8, 2006 03:06 PM

I reckon that's like saying Aspartame (Or any other artificial sweetener) and Sucrose (Natural Sugar) are the same (They're not)

I don't know the structure of Indigo dye (Synth and Natural) though.

Edited by Tabris on May 8, 2006 at 03:12 PM

--- Original message by Tabris on May 8, 2006 03:12 PM

It is similar to the Aspartame/Sucrose analogy but not identical. Aspartame is modified to hit the taste buds in a similar way to sugar and produce a similar result but has an important group added on to make it have no caloric value. Synthetic indigo would not need to have that modified chemical structure. Manufacturers of synthetic indigo would want it to be identical to have the same effect, much like ibuprofen generic producers want their product to be the same as Advil.

If it is a question about natural vs. synthetic indigo then the use of natural indigo would make it not so particular to Japan. On another note, what is the quality of natural indigo that would make it fade faster than sythetic? I would assume that the two are molecularly identical (or are they not entirely?) and should produce identical results. The one difference that could be possible is that natural and synthetic would have different impurities that would effect there respective abilities to be released from the fabric?

What is it exactly that makes japanese denim better/break-in faster than denim fabrics from elsewhere? I mean, if you go from a theory that assumes that indigo is released through two ways (1. Heavy stress/friction in certain areas that will loose indigo from the actual fabric; 2. Introducing indigo into a water/soap solution that will dissolve indigo from the fabirc, albeit at an even rate throughout the enitre jean and not just centered in high stress areas), what is it about the actual dyeing process and fabric quality that will allow for faster indigo loss in high stress areas but more indigo retention in low stress ones? Is there something about the indigo used for dyeing, the process of dyeing, fabric dye retention qualities, or (most likely) a combination of all of the above? Why would any of this be specific to Japan? I would assume that all of the above criteria could be replicated anywhere else in the world. Sorry if all of this has been covered in previous posts, etc. but I am curious.

pm'd