Shared alpaca does not make a close match
DROPS Air contains 65% alpaca, 28% polyamide and 7% wool. Ultra Alpaca contains equal portions of alpaca and wool. More significantly, Air publishes 17 stitches per 4 inches / 10 cm, while Ultra Alpaca publishes 20. Their label gauges do not overlap. Ultra Alpaca should not be treated as a direct replacement for an Air pattern on this evidence.
Construction and length tell another part of the story
DROPS describes Air as fibers blown into a tube. Ultra Alpaca’s construction remains unverified here. Air has 150 m in a 50 g ball, equivalent to a calculated 300 m per 100 g; Ultra Alpaca has 200 m in 100 g. Even equal total length would carry a different yarn mass. Do not assume you can keep both the original garment weight and fabric by changing needle size.
A US listing is only one part of the decision
Yarn.com provides a checked US retailer listing for Ultra Alpaca. No US listing for Air has been verified in this launch dataset; the manufacturer’s US-facing store selector includes overseas sellers. Dollar pricing alone is not evidence of US dispatch. We do not label those overseas sellers as US retailers.
When to stop a substitution attempt
If a sample at the pattern’s stitch gauge is too open, too dense, or otherwise wrong for the garment, choose another candidate or a pattern intended for the yarn. Do not force this comparison to work because the fiber names overlap. Both published care instructions call for hand washing and flat drying, but that shared care category cannot resolve the gauge and construction differences.
Specification sources: DROPS Air. Berroco Ultra Alpaca. Sources and retail evidence are detailed below. These are desk comparisons; no physical testing has been performed.