The “starch challenge” to make blackened denim with glue

Inspired by the red clay challenge I saw on Instagram, I started a starch challenge.

What is the Starch Challenge? You may be wondering, so I will explain.

Interview with Mr. Tsujimoto, President of McCoy’s

The original article is unknown, but it’s about vintage denim that may have darkened and faded.

In the past, we used natural materials such as starch and cornstarch for glue. So when rigid denim was worn in the sun, the glue would oxidize and change color, turning it a light brown.”

that’s so. I also see that in the past, many people wore jeans without removing the glue, and I often see whisker and bites with sharp angles.

Perhaps it is a hard fabric with glue still on it → repeated standing and sitting → the glue fixes the whiskers → physical labor rubs off that hard fabric.

This will cause dramatic whiskers and bites, and the fabric will darken due to oxidation of the glue. This is my tentative theory.

In addition to this, I believe that the denim was also colored by the red soil and water rust.

Vintage denim weft is not white (some are).

Regarding color changes due to oxidation, besides indigo oxidation, oxidation of the weft yarns is also noticeable.

It is unlikely that the same Levi’s 501 would have a different weft color or be dyed with grass or trees, so if you look at the reverse side of a vintage denim and see a browning of the fabric, it is still an effect of oxidation or coloring.

Weft color variation also affects the color impression.

Denim is woven with indigo-dyed warp and undyed weft yarns.

The indigo color variation is, of course, another factor that makes the color appear blacker, as is the undyed weft yarn.

The weft yarn is not dyed, so of course it does not affect the color of the indigo itself. However, when the fabric is rubbed and the weft threads peek through, if the weft threads are not white, the fabric will look more blackish.

The Starch Challenge

Finally, the main issue.

I don’t know how much change I will see since it will be done on non-rigid denim, and since I will continue to wear glued denim, I honestly don’t have the confidence to discern the change in indigo.

So, I will look at oxidation by starch in terms of changes in the weft, the lining.

Jeans Denim Glue Starch

Since it is difficult to tell the change in a single pair of denim, I will compare a few pairs of jeans to see the change.

The original weft color is totally different, but if it is closer to the darker colored full-count brown cotton and Nylon’s denim, I deem that there was an oxidizing effect from the glue.

(from left to right) Warehouse LEE boys motif, Denime’s 10th anniversary, Full Count WWII, Silverstone’s XX, and Nylon’s XX.

Full Count uses brown cotton for the limited edition models it releases each year, I thought it would be the darkest color, but surprisingly, Nylon is the darkest.

The fabric is a FOB production model, but it is probably dyed with grass and trees.


If it starching it as if it were in the same condition as the rigid, I will not want to wear it, so we will apply a starch-filled glue, slightly thicker than the typical starch after washing.

Repeat it every time you do laundry.

The glue will be made from potato starch because cornstarch was not available at the nearby supermarket.

how to make

1. prepare starchy powder (I live in Thailand, so this is Thai).

2. add the flour to the water, stir well, and heat.

One heaping spoonful per 600 ml of water will crisp two pairs of denims to some degree.

(This time I was in the mood for a heavy-duty glue job, so I added two heaping cups.)

3. warm over high heat, stirring constantly. On low heat, stir every 20 seconds to prevent spreading.

After 1~2 minutes on high heat, it will gradually become transparent.

This is where the mixture becomes sticky and easy to spread, so reduce the heat to low.

4. when the whole mixture becomes transparent, it is ready to use.

5. Mix this well with enough water to soak the denims.

I have it on the tub, but for no particular reason. I don’t currently have a washing machine, so I just do this for crying out loud.

About the density of glue

Two heaping spoons in 600 ml of water, as in this case, will make it quite crispy when placed in a minimal amount of water.

There is a slight sting at first when worn after drying, but it is at a level that you quickly get used to.

This time, since I am aiming for aging by gluing, it should really be thinner, but since I do a lot of washing, I wanted to give it a little bite, so I made it a little thinner.

Bad effects of gluing

leave traces of glue

I think the fact that I do this by hand has a lot to do with the fact that I get glue marks on denims.

The thicker the glue, the more likely it is to leave glue marks, especially on the area in contact with the clothesline when drying.

Of course, it will come off if you wear it, but it also looks like it has dust on it, so if you are going to wear it right out, you may want to lighten the concentration.

Tend to smell bad

Even if you think you have dried it well, the smell is noticeable when drying on a cloudy day.

Does it react with sweat? When my denim get a little steamy, they tend to smell fresh and dry.

They get stinky after wearing them for a day, and I repeatedly dry them in the sun to prevent the smell from occurring, but I hesitate to wear them if I have to sweat.

This is quite stressful, so if you just want to keep some of the starchiness, it is a good idea to add a little to commercial laundry glue.


This experiment is going to take a long time, so I have no idea when the next report will be, but please be patient.

created by Rinker
¥1,599(2024/04/23 21:56:06時点 楽天市場調べ-詳細)