How does baby weight yarn compare to 4 ply?

[TooTicky]

Please and thank you

If you are talking olde-style white acrylic baby yarn then it is usually 4 ply
But in these designer days we have baby chunky cashmerino and all sorts of poncetastic lovelies available

When I crochet stuff from 'vintage' patterns, I find even the garments that are made from Twilleys Lysbet (which was 3 ply, I believe) crochet up fine in a 4 ply cotton. I would imagine it would be the same with wool.

It's for toddler socks. The pattern specifies "baby weight yarn" and I have lots of 4 ply which is usual for socks, isn't it?

Yes, I have used 4 ply for knitting baby socks. It was fine.

Thanks