There is a peculiar paradox at the heart of every vacuum insulated travel tumbler: the most important part of the object is the part that isn’t there. The void — the nothing between the two walls of your Yeti, your Thermos, your Zojirushi — is doing nearly all the work. Manufacturing that nothing, reliably, at scale, and for under thirty dollars retail, is one of the more quietly remarkable achievements of modern consumer goods production.

Let’s walk through how these things are actually made.

The Physics You’re Manufacturing Around

To understand the manufacturing, you first have to understand what you’re trying to defeat. Heat transfers three ways: conduction (direct contact), convection (fluid movement), and radiation (electromagnetic waves). A vacuum insulated vessel attacks all three. The double wall eliminates conduction by removing the material that would carry heat. The vacuum between those walls eliminates convection by removing the air that would circulate. And a reflective coating — typically a thin layer of copper or silver deposited on the inner surface of the outer wall — bounces radiant heat back toward the liquid.

This is the same principle Sir James Dewar exploited in 1892 at the Royal Institution in London, when he invented what we now call the Dewar flask for storing cryogenic gases. Dewar never patented the consumer application. That was left to two German glassblowers and businessmen, Reinhold Burger and Albert Aschenbrenner, who commercialized the glass vacuum flask under the name Thermos starting in 1903. For decades, these were glass vessels — fragile, elegant, and良好的 at keeping things hot or cold, but useless on a job site.

The shift to stainless steel vacuum vessels — the thing that made the modern travel tumbler possible — required solving a genuinely difficult manufacturing problem: how do you create and maintain a vacuum between two rigid metal walls, one nested inside the other, while also welding the joint so perfectly that no air leaks in over years of use?

How a Modern Vacuum Tumbler Is Made

The process, as practiced by major manufacturers from China’s OEM factories to brands like Yeti, Zojirushi, and Stanley, follows roughly these stages:

1. Deep Drawing the Steel. The tumbler begins as a flat disc of food-grade stainless steel — typically 18/8 (304 grade), chosen for corrosion resistance and formability. This disc is placed over a die and “deep drawn” — pressed by a punch into a cylindrical shape in a single, forceful stroke. Lubricants reduce friction. The cup is drawn in multiple stages if the height-to-diameter ratio is large, with annealing (heat treatment) between stages to relieve the work hardening that would otherwise crack the metal.

The result is a seamless inner cup and a seamless outer cup. No welds along the side walls means fewer potential leak paths and better structural integrity. The bottom is formed in the draw; the top edge is trimmed to specification.

2. Surface Treatment and Coating. The outer surface of the inner wall (and sometimes the inner surface of the outer wall) receives a reflective coating. In some manufacturing processes, this is a copper flash deposited chemically. In others, it’s a thin film of aluminum applied via physical vapor deposition. This layer is what reflects infrared radiation back toward the liquid — without it, a vacuum alone would still allow significant radiative heat loss. The walls are then cleaned, degreased, and inspected.

3. Assembly and Welding. The inner cup is nested inside the outer cup. The two are joined at the rim — the crucial “mouth” of the vessel. This joint is typically TIG (tungsten inert gas) welded or laser welded to create a hermetic seal. At this stage, there is still air between the walls. The vessel is, in effect, a sealed double-walled container full of atmosphere.

4. Vacuum Evacuation. This is the step that separates a real vacuum insulated tumbler from a cheap imitation. A small evacuation hole — sometimes called a “getter tube” — is left in the bottom of the outer wall. The assembled vessel is placed in a vacuum chamber, and the air is pumped out through this hole. Once the desired vacuum level is reached (typically on the order of 10⁻³ to 10⁻⁴ Torr, though manufacturers rarely publish exact figures), the hole is pinched shut and welded closed.

Some manufacturers use a “getter” — a small amount of material (often barium or a similar reactive metal) that absorbs residual gases over the life of the product, maintaining the vacuum even if microscopic amounts of gas slowly desorb from the metal surfaces.

5. Finishing. The bottom is capped, feet or a non-slip pad are applied, the exterior is powder-coated or given whatever finish the brand specifies, and the lid (a whole separate manufacturing story involving injection-molded polypropylene, silicone gaskets, and sometimes additional vacuum-insulated components) is assembled and tested.

The Seemingly Simple Parts That Aren’t

The lid deserves its own article, but from a manufacturing standpoint, it’s worth noting that the lid is where most of the thermal engineering actually lives. A vacuum insulated wall is only as good as its weakest point, and the lid — which must, by definition, open — is typically that point. This is why high-end tumblers use thick lids, double gaskets, and sometimes even vacuum-insulated steel in the lid itself. Zojirushi’s mugs, for instance, use a sophisticated multi-piece lid with a teflon-sealed opening mechanism that minimizes the heat path from liquid to outside air.

Where They’re Made

The vast majority of vacuum insulated stainless steel tumblers — regardless of the brand on the label — are manufactured in a cluster of factories in and around Guangdong province, China, particularly in cities like Yongkang (in Zhejiang, actually — a major hub for drinkware) and Shenzhen. The deep-drawing equipment, vacuum pumping stations, and welding robotics represent significant capital investment, and the economies of scale favor large, specialized producers.

Yeti, Hydro Flask, and most other major Western brands use contract manufacturers in this region. Stanley (now owned by PMI Worldwide) has its own manufacturing relationships. Zojirushi, the Japanese brand often regarded as making some of the best-insulated tumblers in the world, manufactures many of its stainless steel mugs in Thailand, a detail the company discloses on its packaging.

This is not a secret, and it’s not a knock on quality. The same factories producing a $40 Yeti may also produce a $12 store-brand tumbler to a different (thinner walls, less rigorous vacuum, cheaper lid) specification. The manufacturing process is similar; the tolerances, materials, and quality control differ.

What Makes a Good One

If you’re shopping for a vacuum insulated tumbler and want to evaluate manufacturing quality rather than marketing, here are the things that actually matter:

Wall thickness. Thicker stainless walls hold their shape better under denting and provide more thermal mass, though the vacuum does the insulation work. Premium tumblers typically use 0.4–0.6mm 18/8 stainless. Thin-walled budget tumblers dent easily.

Vacuum quality. You can’t see this, but you can infer it. A well-evacuated tumbler will have virtually no condensation on the outside when filled with ice water, and the outside won’t get hot when filled with boiling water. If the outside sweats or warms noticeably, the vacuum has degraded or was never good.

Weld quality. Look at the rim where inner and outer walls meet. A clean, smooth weld suggests better manufacturing control. Rough or uneven welds are a red flag for long-term vacuum integrity.

Lid design. This is where most heat escapes. Look for thick lids, good gasket compression, and minimal open-area when the drinking port is closed. Magnetic closures (like Yeti’s Rambler lids) are clever but not necessarily better thermally than well-designed push-button seals.

Buying Guide

If you want to explore options, here are some search links to get you started:

A Brief Note on the Getters

One detail that rarely surfaces in consumer-facing material: the getter. If you cut open a quality vacuum tumbler (please don’t), you might find a small deposit of silvery or dark material near the evacuation point. That’s the getter — a sacrificial material placed inside the vacuum space to scavenge residual gas molecules over the product’s life. The concept comes straight from vacuum tube and CRT manufacturing, and it’s one of the reasons a good tumbler from 2015 still works in 2025 while a cheap one from last year has lost its insulation.

It’s a small thing. But it’s the kind of detail that separates manufacturing that’s merely competent from manufacturing that’s genuinely thoughtful — the difference between an object that keeps your coffee hot for six hours and one that keeps it hot for six hours, five years from now.

Sources and Further Reading