How to Date Vintage Clothing by the Label Inside It
Published 2026-08-17 · Vintage Clothing · Antique Partner
Quick answer: Four US labeling laws date almost any garment. How to read RN numbers, care labels, union labels and zippers to date vintage clothing in under a minute.
Vintage Clothing
How to Date Vintage Clothing by the Label Inside It
By Nicolas · August 17, 2026 · 11 min read
Most people date vintage clothing by how it looks. Silhouette, fabric, the cut of a shoulder. That works, and it is also how you get fooled, because every decade has been revived at least once and a 1990s dress can be cut like a 1950s one on purpose.
The label is harder to fake, because it was never meant to be decorative. Four separate pieces of United States labeling law forced manufacturers to add specific information at specific moments, and each one puts a hard floor under a garment's age. A dress cannot be older than the law that made its label legal.
None of this needs expertise or equipment. Turn the garment inside out, look at the back of the neck and the left side seam, and you can usually narrow a piece to a decade while you are still standing in the shop.
The four dates that do most of the work
These are not rules of thumb. They are federal labeling requirements, and each gives you an earliest possible date . If the feature is present, the garment was made on or after that year. It says nothing about how much later.
If the label has It was made Because of
A WPL number
00101 to 13669
1941 to 1959
Wool Products Labeling Act
Fiber content percentages
“65% polyester 35% cotton”
March 1960 or later
Textile Fiber Products Identification Act, effective 3 March 1960
An RN number
13670 or above
1959 or later
FTC took over registration in 1959
Permanent care instructions
“Machine wash warm, tumble dry low”
1972 or later
FTC Care Labeling Rule, adopted December 1971, effective 1972
That last row is the most useful line in this article, and it works in both directions. A garment with sewn-in washing instructions is 1972 or later, full stop. A garment with no care label at all, where the label is clearly original and intact, is very likely earlier than 1972. Two seconds of looking, fifty years eliminated.
RN numbers, and the mistake almost everyone makes
An RN number is a Registered Identification Number , issued by the Federal Trade Commission to companies that make, import, or sell textile products in the United States. It is five or six digits, printed as “RN 51000” or similar, and the series began at 13670 in 1959 and has been issued in order ever since. The FTC runs a free public database where you can type the number and see which company it belongs to.
Here is the mistake. A higher RN number does mean a later registration, and people use that to date garments. But the RN dates the company, not the clothing . A firm that registered in 1962 kept using that same number in 1985 and in 2005. It gives you an earliest possible date for the garment and nothing more.
Where the RN genuinely earns its place is identification rather than dating. It tells you who actually made a piece when the brand name means nothing to you, which is how you find out that an unremarkable label belongs to a maker worth knowing about.
The back of the neck first, then the left side seam. Between them sit almost every date clue a garment carries.
WPL numbers put you in a nineteen-year window
Before the FTC took over, numbers were issued under the Wool Products Labeling Act , running from 00101 to 13669 between 1941 and 1959 . A WPL number is therefore a much tighter signal than an RN, because the series stopped. If you find one, the company registered inside that nineteen-year window, and in practice the garment is very often from the 1940s or 1950s.
The same earliest-possible-date caution applies, but it matters far less here, because a company registered in that window was frequently gone or renamed within a couple of decades.
Union labels: the sequence collectors have mapped
If a garment was sewn in an American union shop, it usually carries a union label, and the design of that label changed over time. The International Ladies’ Garment Workers’ Union, founded in 1900, revised its label roughly eight times, which is why collectors treat it as a decade-level dating tool.
The broad sequence runs like this. Labels reading “ILGWU” with “AFL” belong to the period before 1936. Through the middle of the century the label moved from simple blue printing to a red, white and blue design in the late 1950s. A revised design was introduced on 28 June 1963 and trademarked the following April. The familiar red, white and blue label with the scalloped circle, needle and thread ran from about 1974 to 1995 . In 1995 the ILGWU merged into UNITE, and the UNITE! label , plain type with a red exclamation mark, covers roughly 1995 to 2004.
One honest distinction is worth making. The four legal dates above are federal law and can be checked against the statutes. The union label sequence is trade knowledge , assembled by collectors and dealers comparing dated garments over many years. It is reliable enough to use and it is not the same kind of evidence, so treat it as strong corroboration rather than proof on its own.
The zipper is not a label, but it does the same job
Zippers changed on a schedule too, and unlike a label a zipper is rarely replaced. The Hookless Fastener Company renamed itself Talon in 1937 , so a Talon-branded zip is 1937 or later, while Conmar, Crown and Serval fill out the same American era.
The bigger shift is material. Nylon coil zippers were invented around 1940 , became common in clothing through the late 1950s and 1960s , and were the standard by the 1970s . A heavy metal zip in a dress or skirt therefore points strongly to before the mid 1960s. Placement helps as well: a metal zipper in the left side seam is a classic 1940s and 1950s arrangement, before centre-back zips took over. On earlier Talon zips the pull is often shaped, sometimes described as bell or sunburst; later nylon zips have a plain flat tab.
Metal teeth in a side seam. Zips are almost never replaced, which makes them steadier evidence than a label that can be cut out.
Reading them together, which is the whole trick
No single tell decides anything. What dates a garment is agreement between several . Take a wool dress with a metal zip in the left side seam, a label listing fiber percentages, no care instructions anywhere, and an ILGWU union label.
Work it through. The fiber percentages mean 1960 or later. The absence of care instructions on an intact original label means very likely before 1972. The metal side zip agrees with both, since it points before the mid 1960s. The union label confirms American union manufacture. Four independent signals converge on the 1960s , and none of them contradicts the others.
Inside out on a flat surface. Four independent signals, checked against each other, beat any one of them alone.
That convergence is the entire method, and it is the same discipline that separates a period antique from a good reproduction. Our guide on how to tell if something is actually antique applies the identical logic to furniture, glass and silver: never hang a decision on one clue, and look hardest at the parts nobody bothered to finish.
What will fool you
Missing labels prove nothing. Scratchy labels get cut out by the original owner constantly, particularly at the back of the neck. An absent label is an absence of evidence, not evidence of age.
No union label does not mean not American. Union labels only ever appeared on garments sewn in union shops. Plenty of American clothing was made in non-union factories, and imported clothing never carried one at all.
Deadstock breaks the logic. Clothing that sat unsold in a warehouse for years carries the labels of its manufacture date, not its sale date, which is correct but can feel wrong when the styling looks later.
The RN trap, once more. It is the single most misused number in vintage clothing. It dates a company registration. Nothing about it tells you when the garment left the factory.
Reproduction labels exist. High-value vintage brands are worth faking, labels included. This is exactly why convergence matters: a faked label sitting above a nylon zip in a garment with modern care instructions falls apart immediately.
Go and read a hundred of them
This is a skill that only sticks with repetition, and the fastest way to build it is a rail of unsorted vintage and twenty minutes. Turn out collars, check side seams, guess the decade, then look for the tells that confirm or kill your guess. Thousands of the shops in our directory carry vintage clothing, and a good one will let you handle everything on the rail.
Find vintage clothing near you
Browse thousands of vintage, antique and thrift stores across the US and Canada, and go practise on a real rail.
Sources
Textile Fiber Products Identification Act, rules and regulations effective 3 March 1960 (16 CFR Part 303).
FTC Care Labeling Rule, 16 CFR Part 423, adopted 16 December 1971, effective 1972.
Wool Products Labeling Act, WPL registration series 00101 to 13669, 1941 to 1959.
Federal Trade Commission Registered Identification Number system, series beginning 13670 in 1959; public RN lookup maintained by the FTC.
ILGWU label chronology and zipper manufacturing dates compiled from vintage trade and collector reference sources, including the ILGWU records held by the Kheel Center at Cornell University’s ILR School.
Frequently asked questions
How can I tell if clothing is actually vintage?
Start with the label. Four US labeling laws put hard earliest-possible dates on a garment: a WPL number means the company registered between 1941 and 1959, fiber content percentages mean March 1960 or later, an RN number means 1959 or later, and sewn-in care instructions mean 1972 or later. Combine those with the zipper and the union label, and most garments narrow to a decade.
What does the RN number on a clothing tag mean?
RN stands for Registered Identification Number, issued by the Federal Trade Commission to companies that make, import or sell textiles in the United States. The series began at 13670 in 1959 and has been issued in order since. You can look any RN up free in the FTC database to find the company. Importantly it dates the company registration, not the garment, so it only gives you an earliest possible date.
When did clothing labels start showing washing instructions?
Permanent care labels became a federal requirement under the FTC Care Labeling Rule, which was adopted in December 1971 and took effect in 1972. That makes them one of the most useful dating tools there is: a garment with sewn-in washing instructions was made in 1972 or later, and an intact original label with no care instructions usually means earlier.
Does a metal zipper mean clothing is vintage?
It is a strong signal but not proof. Nylon coil zippers appeared around 1940, became common through the late 1950s and 1960s, and were standard by the 1970s, so a heavy metal zip points to before the mid 1960s. A metal zipper in the left side seam is especially characteristic of 1940s and 1950s dresses and skirts. Metal zips are still made today, so read it alongside the label rather than on its own.
What does a union label tell you about a garment?
It tells you the piece was sewn in an American union shop, and the label design narrows the era. ILGWU labels changed roughly eight times from 1900 onward, moving from blue printing to red, white and blue in the late 1950s, a revised design in 1963, the familiar scalloped circle from about 1974 to 1995, and the UNITE! label from 1995. Note that the absence of a union label means nothing, because non-union and imported garments never carried one.