Fabric defect · Dyeing and printing - Water spots on fabric: causes and how they count

A water spot is a mark left where water reached the fabric. In the mill it can come from steam condensing and dripping in a steamer, from drops on yarn as it is steamed, or from goods left wet in a box or roll. Some dyes and finishes also spot when water touches the finished fabric.

A pale, blotchy spot on the face of the fabric, outlined in cyan.

What ConductVision Textile records

ConductVision Textile is designed to flag each defect with its place on the roll, its size, its points and a still image. Your inspector names the defect and confirms or dismisses it.

On the defect map in the roll report, a water spot is a spot.

Fabric inspectionDefects, points and a final points forecast

What water spots are

A U.S. federal glossary of fabric imperfections defines a spot or stain as "an area of discoloration on the surface of the cloth" ¹. Cotton Incorporated's defect glossary shows water damage, "the result of a fabric being wet after finishing and allowed to remain in a box or roll. The color tends to migrate leaving the fabric blotchy" ².

Not every water mark is a fault. Moiré is a finish made by pressing fabric between engraved rolls "to create a watermark appearance" ³. As a defect, Goldberg notes, "moire, or water-impression, marks" are likely on plain woven or faille-type rayon fabrics batched up in open width while still wet ⁴.

What causes water spots

Goldberg counts water among the things that can contaminate cotton at every step in the mill: condensation from vapors overhead, leaks from pipes and roofs, and careless splashing ⁴.

What causes water spots
Stage	What happens	What to check
Steaming prints	Water spots in a print steamer are "almost always due to improper or insufficient maintenance." When clogged traps cut off the steam coils, steam can condense and drip onto the fabric before the dye is fixed ⁵.	Steam traps and coils, clean and working
Steaming prints	Cotton Incorporated says steam in the steamer should be saturated and slightly overheated, at 103°C (217°F). This "prevents water spotting in the steamer" ⁶.	Steam condition and temperature
Storing prints	Printed fabric that is not yet fixed can be stored indefinitely if it is protected from water spots and other contaminants in the store ⁵.	Covered, dry storage for printed goods
Twist setting	In one of Goldberg's cases, drops of water condensed on acetate yarn while it was steamed to set its twist. At high temperatures, above all where the yarn touched the hot metal heads of the spools, the water spots partly delustered its surface ⁴.	Condensation during yarn steaming
Batching and washing	Rayon batched in open width while still wet can take moiré, or water-impression, marks ⁴. Moiré can also appear on some woven and warp knit fabrics that are beam washed ⁷.	Wet goods batched in open width, and beam washing
Sizing and finishing	Gray goods made up with the warp size left in for stiffness spot when water partly dissolves the size and the wet warp shrinks ⁴.	Water-soluble size or stiffener left in the goods
Dyeing and finishing	A dye "sensitive to both moisture and dry heat," or a finish "sensitive to water-spotting only," leaves goods that spot when they are wetted or pressed. Goldberg puts both faults on the dyer ⁴.	Dyes and finishes tested for water spotting
After finishing	Fabric left wet in a box or roll after finishing lets the color migrate, and the fabric turns blotchy ².	Goods dry before they are boxed or rolled

Where water spots show on a roll

Water spots take more than one form. On acetate yarn, they showed in the woven fabric as "short light streaks in the filling" ⁴. On unfinished gray goods, water left a puckered, spotted area ⁴, and fabric left wet in a roll turns blotchy ².

Defect positionWhat a defect's place on the roll points to

How water spots count

Every defect visible at normal inspection speed and from one yard or one metre is counted ⁸. On the 4-point scale a spot scores 1 point up to 3 inches, 2 points over 3 up to 6 inches, 3 points over 6 up to 9 inches and 4 points over 9 inches ⁹.

Cotton Incorporated's defect glossary rates its water damage example a major finishing defect ². Its grading guide defines a major defect as one severe enough, if exposed, to make the end item a second ⁸.

Colorfastness to water spotting has its own test method, AATCC TM104 ¹⁰.

What research says

In his 1950 casebook, Goldberg traced short light streaks in the filling of a fabric to drops of water on acetate yarn as its twist was set with steam. To confirm it, water drops were put on yarn on purpose during steaming, and the packages were woven into the filling of a marked piece. "Laboratory dyeing of head ends disclosed the same type of defect" ⁴.

In another case, a customer found that a fabric showed spots during pressing. Samples were spotted with water in the laboratory, some pressed with a hand iron and some left to dry, and the tests were repeated after scouring. "It was found that only the purple-dyed cutting spotted easily both in the original state and after scouring." Goldberg concluded that the purple dye was sensitive to moisture and dry heat, and that a finish on the blue fabric was sensitive to water alone ⁴.

A garment was stained by water spots that dry-cleaning solvents did not remove. It had been made from gray goods with the warp size left in for stiffness, and the size partly dissolved where water touched it. Similar taffetas that held no water-soluble stiffener did not have the problem ⁴.

Sources

Pilot - How a pilot starts

We start with recorded video of your inspection frame and agree with your team on one fabric to test. The pilot runs for a set time, and before it starts we agree on what counts as success. For each defect it marks, ConductVision saves a still image and its place on the roll on your network for your inspector to check.

You bring: Recorded video of fabric running over your inspection frame
We set up: One fabric, and the limit you grade it against
You get: Marked defects, running points and a final points forecast for each roll, and a results report checked against what we agreed

One question to start with

Which fabric shows water spots most often?

Plan a pilot