Inside the side seam of an old dress, or tucked under the main label of a wool blazer, you sometimes find a second, smaller tag. It might be a narrow strip printed in blue and white, or a little red, white and blue rectangle with a few lines of tiny text. It does not tell you the size or the brand. It tells you that the people who sewed the garment belonged to a union, and in doing so it offers one of the more interesting clues in vintage clothing.
Union labels sit quietly in the background of a lot of mid-century North American clothing. Many people never notice them. Collectors, though, have spent years studying them, because the labels changed in recognisable ways over the decades. This guide explains what union labels are, where you are most likely to find them, and how collectors use them alongside other details when thinking about whether a piece is authentic vintage, always as a clue rather than a verdict.
01. What a union label actually is
In the early twentieth century, garment work in North America was often poorly paid and dangerous. Workers organised into unions, and over time those unions negotiated better wages and conditions with manufacturers. A union label was a way of telling shoppers that a garment had been made under those agreements.
The label was partly a guarantee and partly an advertisement. Unions ran public campaigns encouraging people to look for the label when shopping, with the idea that buyers could support fair working conditions through what they chose to buy. For decades, a union label was something many shoppers recognised and some actively sought out.
For the vintage buyer today, the label's original message matters less than its secondary function as a historical marker. Because unions changed their names, merged with each other and redesigned their labels over the years, the version you find in a garment can help place it within a broad window of time.
02. The unions you will meet most often
Several unions issued labels, and the main ones are worth knowing by name.
The ILGWU
The International Ladies' Garment Workers' Union represented workers making women's clothing: dresses, blouses, skirts, coats and more. Its label is probably the one vintage shoppers encounter most often, especially in women's garments from the middle decades of the century. Over the years the ILGWU label went through several designs, with changes in colour, wording and layout, and collectors have built up reference material that groups these into rough periods.
The Amalgamated Clothing Workers of America
The ACWA represented workers in the men's clothing trade, including suits, coats and trousers. Its labels appear in tailored menswear, often near the inside pocket or the maker's label. In the mid-seventies, the ACWA merged with a textile workers' union to form the Amalgamated Clothing and Textile Workers Union, known as ACTWU, and labels from after that point carry the new name.
Later mergers
In the mid-nineties, the ILGWU and ACTWU merged into a single union called UNITE, and in the following decade UNITE merged with a hospitality workers' union to become UNITE HERE. Each of these name changes left its mark on labels, which is precisely why collectors find them useful.
Hats, gloves and other trades
Other unions represented hat makers, glove makers and specialist trades. Union labels or stamps occasionally turn up inside the sweatband of a fedora or on the lining of other accessories. They are less studied than the big garment union labels, but they follow the same logic.
03. How collectors use them
The core idea is simple. If a garment carries a label from a union that only existed under that name during a particular period, the garment was probably made during that period. A label reading ACTWU, for example, suggests the garment was made after the mid-seventies merger. A label reading UNITE points to the mid-nineties or later.
The ILGWU label is more detailed. Because its design changed several times while the name stayed the same, collectors compare the colours, the wording and the layout against reference examples to suggest a narrower window. Some versions are associated with earlier decades, others with later ones. Exact dates for each design are debated, and different references sometimes disagree slightly, which is a good reminder to treat any single dating as approximate.
Union labels are most useful when combined with other information: the style of the garment, the fabric, the zip, the construction, the main brand label and any care or fibre-content tags. When all of these point to the same rough period, you can feel reasonably confident. When they disagree, it is worth looking more closely.
A union label is a small witness, worth listening to, but never the only one you should call.
04. What a union label cannot tell you
It is easy to lean too heavily on these labels, so it is worth being clear about their limits.
- They do not prove age on their own. Labels were sometimes used for longer than you might expect, and old stock could be sewn into garments made later.
- They can be moved or added. Labels can be unpicked from one garment and sewn into another. It is not common, but it happens, especially with desirable pieces.
- They can be reproduced. Reproduction garments, made to look old, sometimes include copies of vintage-style labels.
- Their absence means little. Many vintage garments were made by non-union workers, or outside North America, and never had a union label at all.
- They say nothing about quality. A union-made garment may be beautifully made or very ordinary.
The sensible approach is to treat a union label as one witness among several. It can support a conclusion you have reached through other clues, or prompt you to look more carefully, but it should not settle the question by itself.
05. Where to look on a garment
Union labels hide in a few typical places. In women's dresses and blouses, check the side seam, often a few centimetres below the armpit, where a small label might be sewn into the seam allowance. Some are attached just below the main brand label at the back of the neck. In skirts and trousers, look along the waistband or inside a side seam.
In men's tailoring, union labels often sit near the inside breast pocket, sometimes stitched along the edge of the maker's label or the pocket lining. In coats, they may be in the lining near the hem or close to the collar.
Look carefully at how the label is attached. A union label sewn in with the same thread and the same kind of stitching as the surrounding seam is reassuring. One that looks freshly sewn, with brighter thread or uneven stitches, may have been added later and deserves a second look.
06. Union labels and Canadian clothing
Most of the labels collectors discuss come from the United States, because that is where the large international garment unions were based and where most of the reference material comes from. The ILGWU in particular had members in Canada, and Canadian garment workers in cities such as Montreal, Toronto and Winnipeg also organised over the twentieth century.
That means you may find union labels in Canadian-made clothing too, sometimes with bilingual text or with wording that differs from the more familiar American versions. These are less documented, and it is harder to find reliable reference material on them. If you find one, treat it as an interesting detail of the garment's story and use other clues for dating.
For anyone shopping vintage in Toronto, which had a substantial garment industry around Spadina Avenue for much of the century, these labels are a small reminder of the local workers who made many of the clothes that now turn up on second-hand racks.
07. Reading a garment as a whole
Here is how a union label might fit into a typical check. Say you find a wool dress with a fitted waist and a metal zip down the back. The main label is from a brand you do not know. Inside the side seam is an ILGWU label in a design that collector guides tend to associate with roughly the sixties.
That label agrees with several other clues: the metal zip, the construction, the cut. Together they suggest a garment from around that time. None of them alone would be conclusive. Together, they make a reasonable case.
Now imagine the same label in a dress with a plastic zip, a printed care tag in a modern format and an overlocked seam finish typical of much later production. The label would then be the odd one out, and you would want to think about why. Perhaps the label was reused, or perhaps the garment is a reproduction. The disagreement is the useful part.
08. Learning the labels without obsessing
If you enjoy this sort of detail, union labels are an approachable subject to study. Start by looking at every one you come across and noting the colours, wording and layout. Over time, you will begin to recognise the main versions without needing a reference chart. Collector forums and books on vintage clothing often include illustrated guides, though it is worth comparing more than one source.
If detail is not your thing, the essentials are enough. Know that a union label exists, know the main union names, and know that it is a clue rather than a guarantee.
09. A quiet piece of history
When you next find a small union label tucked into a seam, take a moment with it. It represents a long history of people who worked hard for fair conditions, and it is a genuinely useful detail for understanding when and how a garment was made. Combined with the fabric, the fasteners, the cut and the brand label, it helps you build a sound picture of the piece in your hands.
When looking through the racks at Queen St or Square One, or anywhere else you shop, let the union label be part of your reading rather than the end of it. The best authentic vintage purchases come from looking at everything a garment has to say, and this small tag has more to say than most.
