About A Chair AAC 21 swivel chair by Hee Welling

HAY introduces the AAC 21 as "tempering the more formal expression of the aluminum swivel base with the softness and warmth of the upholstered shell." The same dimensions and base as the AAC 20, available in standard or quilted upholstery.

The upholstered shell, and what the textiles are

The shell is the same as the non-upholstered models, a molded recycled polypropylene—that is what HAY's product sheet states—but here it is fully covered. Foam is placed over the shell and then dressed in the chosen fabric: the feel is softer and sound is better dampened in high-traffic rooms. Conversely, upholstery must be cleaned by blotting rather than spraying.

The fabrics offered here: Hallingdal 65, a Kvadrat wool (70% wool, 30% viscose), the company's classic, very durable; Sense, HAY's through-dyed aniline leather: it reveals the grain and develops a patina with use; Bolgheri, a rich HAY fabric blend (viscose, wool, polyamide, silk, linen); Linara, a Romo cotton and linen fabric (63% / 37%) with a matte look; Remix 3, a heathered Kvadrat wool (92% wool, 8% nylon). The so-called quilted variants—HAY uses the term quilted—feature topstitching that divides the upholstery: the padding does not shift over time, and the texture breaks up the solid surface.

The swivel base: cast aluminum, polished or powder-coated

The base is a piece of cast aluminum—HAY writes cast aluminum swivel base—with four legs spreading from a single center. The shell rotates on this base. The glides are standard glides, not casters: the chair turns on itself but does not move on its own, making it more suitable for a meeting or dining table than a workstation.

Two finishes. Polished aluminum is bare, shiny metal whose luster comes from mechanical polishing: it shows fingerprints slightly and can be revived with a soft cloth. Black powder-coated aluminum receives a kiln-baked powder finish: a thick, matte layer that is more resistant to impacts. HAY presents this base as "a more formal expression" than the wood-legged models.