HELP! Clark Knitting Pins Vintage Pattern

I’m trying to read a vintage knitting pattern which is telling me to use ‘Clark’s O.N.T. Knitting Pins, 1 pair No. 1 and 1 pair No. 3.’

Is this UK, US or Canadian? What is the modern measurement of these needles?

Thank you!!

Welcome to KH!
Does the pattern give a gauge or tension? Can you give us a link to the pattern or a pattern name?

There’s the pattern. It says 7.5 sts for 1 inch and 10 rows per inch.

OK, thanks. It’s close to US sizes. I’ve seen a Coats needle defended as a 2mm or a U.S. 1 although this chart calls 2mm a U.S. 0. At any rate, it’s close. Best to do a swatch to make sure of your gauge with your yarn.
Lovely pattern which will look adorable, I 'm sure.

Thank you :smiley: I will post pictures when I’m finished.