I’m very new at knitting - trying to teach myself. My first project was a knit hat, made in ribbing. Turned out very cute. It was hot pink and yellow. It is soft, and the size I intended it to be for my granddaughter.
I bought more yarn (maroon and blue) and made another, exactly the same way, for my grandson. It turned out much larger and not nearly as soft. It’s the same brand and style of yarn – the only difference is the colors.
I looked closely at the stitches and they do not appear to be looser, so I’m sure that’s not it.
Oh, the only other difference was I used the right hand for one to “throw” the yarn around the needle. On the second one I used the technique of having the yarn in the left hand (which I like better). Could that have made a difference? If anything, I think the knitting was tighter on the second one (that turned out bigger).