Witzend
*GrannyLaine*, I happen to have made dolls’ blankets for a Gdd using double DK and 6 mm needles (nice and quick!) which is what the pattern I quoted uses. They do come out nice and soft and ‘wrappable’, not thick or firm, so I do think they’d be fine for very small babies.
Of course the end product would be much firmer and less conformable if rather smaller needles were used.
The only thing the original ‘ask’ says, is that there should be no holes that might trap very tiny fingers.,
No offence was meant Witzend, simply that if someone is going to the trouble of knitting blankets, it's worth getting it just right. I've worked in special care units and not everything that is donated is useable, despite being made with the best of intentions. There's also the consideration that they are used in incubators where thermoregulation is a priority.