If you are planning a denim drop, the acid wash vs stone wash decision will shape almost everything that follows: the base fabric you choose, how the pattern is cut, how the sample is approved, and how many pieces you need to order. I’m Ken, and I run SEASANG Apparel, a garment factory in Humen, Dongguan. We make jeans and denim trousers for independent brands, and the wash is the part of a denim order where most misunderstandings happen. This guide explains what each wash really is, what changes in the finished garment, and how to describe the wash so the factory gives you what you have in your head.
What stone wash and acid wash actually are
Both are garment washes. The jeans are sewn first from unwashed (rigid or raw) denim, then the finished garments go into large industrial washing machines at a wash house. The difference is what goes into the drum with them.
Stone wash
Stone wash uses pumice stones tumbled with the jeans in water. The stones rub against the fabric and knock indigo off the surface yarns. Because indigo sits mostly on the outside of the yarn, the abrasion reveals the lighter core underneath. The result is an overall, fairly even fade with softer hand feel. Many wash houses now combine stones with enzymes, or replace part of the stones with enzymes, to get a similar effect with less damage to the fabric and the machines. You will often see this called “enzyme stone wash.”
The intensity is controlled by time in the drum, the amount of stones or enzyme, and how many cycles are run. A short cycle gives a dark, slightly softened blue. A long cycle gives a light, worn-in blue.
Acid wash
Despite the name, acid wash does not normally use acid. The usual method is to soak pumice stones in an oxidising chemical, most often potassium permanganate or a bleach solution, and tumble them with the jeans with very little or no water. Wherever a stone touches the fabric, colour is stripped away hard and fast. Where it does not touch, the original colour stays. After the effect is reached, the garments are neutralised and rinsed so the chemical stops working.
This gives the high-contrast, mottled, marbled look associated with 1980s denim and a lot of current streetwear. It is not an even fade. It is a pattern of light and dark patches, and no two garments come out identical.
Acid wash vs stone wash: side-by-side comparison
The table below summarises what you can typically expect. Exact results depend on the base fabric and the wash house recipe.
| Point | Stone wash | Acid wash |
|---|---|---|
| Main agent | Pumice stones and/or enzymes in water | Pumice soaked in an oxidiser (often permanganate or bleach), little or no water |
| Look | Even, overall fade; classic worn blue | High-contrast, marbled or speckled pattern |
| Variation between pieces | Low to moderate | High; every piece is slightly different |
| Hand feel | Soft | Soft but can feel drier; usually softened afterwards |
| Fabric strength | Some loss from abrasion | Usually more loss, because of chemical plus abrasion |
| Works on black denim | Yes, fades to charcoal or grey | Yes, very common; gives grey and black marbling |
| Easy to repeat in reorders | Fairly easy with a recorded recipe | Harder; you match a range, not an exact copy |
How each wash affects shrinkage and fit
This is the part brands most often underestimate. Rigid cotton denim shrinks when it is washed, and garment washing is a hot, long, mechanical process. Typical shrinkage for unwashed rigid cotton denim is a few percent and can be higher in length than in width. Stretch denim with elastane behaves differently again, and can shrink more in the width.
Because the jeans are sewn before they are washed, the pattern has to be cut larger than the final size by the expected shrinkage. That allowance is not the same for every wash:
- A light rinse shrinks the fabric less than a long stone wash.
- A long stone wash with heat and many cycles usually gives the most shrinkage.
- Acid wash is often done after a rinse or desize step, so its total shrinkage depends on the whole sequence, not just the acid step.
- Different denim lots, even of the same fabric quality, can shrink slightly differently.
In practice this means the factory needs to do a shrinkage test on your actual fabric with your actual wash, then adjust the pattern. If you skip this and use one pattern for three washes, you can end up with the light wash fitting one size smaller than the dark one. When you approve a sample, measure the washed sample against your spec sheet, not the unwashed one.
Also check details that react to washing: pocket bags, labels, and thread. Cotton thread fades with the denim; polyester or core-spun thread mostly keeps its colour, which is why stitching on washed jeans often looks brighter than the fabric. Metal buttons and rivets can discolour in some chemical washes, so tell the factory if the hardware finish matters to you.
Choosing the base fabric for each wash
The wash can only work with what the fabric gives it. A few practical points:
- Indigo depth: a deep indigo denim gives more room for a stone wash to create contrast. A pale base will look washed out quickly.
- Black denim: for a grey or black acid wash, the dye type matters. Sulphur black and overdyed denims fade differently, so ask for a wash test on the fabric before committing.
- Weight: heavier denim survives aggressive washes better. Lightweight denim with a strong acid wash can thin out at seams and edges.
- Stretch content: elastane can be weakened by harsh chemicals and heat. If you want a heavy acid wash, rigid or low-stretch cotton is usually safer.
We source denim to the client’s spec, so if you already know your weight and composition, send it. If you don’t, describe the look and feel you want and we can propose options. You can read more about how we handle denim on our denim manufacturer page.
How to specify the wash to a factory
“Vintage acid wash” means different things to different people. The more concrete your brief, the fewer sample rounds you need. A good wash brief includes:
- Reference photos of the front and back, in daylight, ideally of a real garment rather than an edited product shot. Edited photos often push contrast and colour.
- A physical reference if you have one. A pair of jeans or even a swatch posted to the factory is worth more than any description.
- Base fabric: colour (indigo, black, grey), weight, cotton or stretch.
- Wash type and intensity: for example, “medium stone wash, mid blue,” or “heavy acid wash, strong contrast, mostly light.”
- Extra effects: whiskers, hand sanding on thighs, rips or repairs, tint (a yellow or brown tint over the wash for an aged look), and softener.
- What not to do: if you don’t want whiskers or any damage, say so. Some wash houses add them by default on “vintage” washes.
- Acceptable variation: especially for acid wash, agree that the bulk will fall within a range shown by the approved sample, not match it piece for piece.
Once the sample is approved, ask for it to be kept as the wash standard. For reorders, the wash house works from that standard and its recorded recipe. Without it, reorders drift.
Our sampling takes about 7 to 10 days depending on construction, and bulk production runs about two weeks after you approve the sample. Shipping is arranged separately. The full process is on our sampling and production page.
Why MOQ is counted per wash
Our minimum order is about 100 pieces per style per wash for denim, with sizes split inside that number. Brands sometimes ask why 100 pieces split across three washes doesn’t count. There are a few real reasons:
- Each wash is a separate run. Garments are washed in machine loads with one recipe. A load of 30 pieces still uses the machine, water, stones and chemicals, and the wash house prices and schedules around full loads.
- Each wash needs its own shrinkage test and pattern adjustment. The cutting is done to a pattern adjusted for that wash, so a different wash is effectively a different cutting job.
- Consistency is better in one batch. Pieces washed together match each other more closely than pieces washed in separate small batches, which matters a lot for acid wash.
If budget or risk is a concern, a common approach is to launch one wash at full minimum and add a second wash on reorder once you know what sells. Our low MOQ guide covers how to plan a first order around minimums.
Which wash suits your brand?
Stone wash is the safer, more versatile choice. It works for classic straight and relaxed fits, is easier to repeat, and customers know what they are getting. Acid wash makes a stronger statement. It suits streetwear, oversized or baggy fits, and collections built around a retro look, and it pairs well with heavy graphics on hoodies and tees. If you’re building a full collection around it, our streetwear manufacturing page and acid wash jeans page show what we make alongside denim.
Whichever you choose, plan for one extra sample round on the wash, measure washed samples, and keep the approved sample as your standard.
If you have a design, a reference pair, or just photos of the wash you want, send them through our request-a-quote page. Tell us the fit, fabric and wash, and we’ll come back with questions, a sampling plan and timing for your jeans.
