Reading Hand-Blown Glass

Once you know what to look for, a piece of hand-blown glass more or less tells you how it was made. The evidence is built into the object - you just have to know how to look.

Start with air bubbles. Glass that's blown by mouth traps small pockets of air as it's worked, and those bubbles stay exactly where they formed, frozen in place once the glass cools. They are not a flaw. They are close to unavoidable, and their presence is one of the more reliable signs that a piece was actually blown rather than pressed into a mould, where the process is controlled enough to keep bubbles out.

Look for applied details rather than moulded ones. La Soufflerie's Vase Taka carries a band of glass around the neck that's added as a second step - a separate length of molten glass laid around the body while it's still warm, then fused on by hand. Because it's applied rather than moulded in as one piece, it never sits at exactly the same height or thickness twice. Run a finger around it: if it's genuinely uneven, that's a hand at work, not a machine.

Check the base. Mouth-blown glass is finished off a blowpipe or punty, and the base usually shows some trace of it - a slightly rough patch, a faint scar, sometimes ground flat and polished afterward but rarely machine-perfect. A pressed or moulded piece has a base formed as part of the mould: smooth, uniform, with no sign anything was ever attached or removed.

Hold two "identical" pieces side by side, if you can. La Soufflerie's Vase Boudin Bas, mouth-blown in Paris from recycled glass one piece at a time, will show small differences between units of the same design - a slightly different wall thickness, a band sitting a touch higher or lower. A machine run of the same design won't vary at all, because uniformity is what a machine is for.

Shop our La Soufflerie glassware, mouth-blown by hand in Paris from recycled glass.