I recieved a message within ravelry the other day (rav mail!) from a very sweet knitter, Pam. She gave me permission to repost our conversation here on my blog, I thought it might be of use to those knitting Serendipity who might have the same question!
… I made the infant size yesterday, and want to ask you about the top of the hat. Why did you decide to change to the bigger needles for the top of the hat? The top of my hat is pretty loose, and I am contemplating taking it back to the beginning of the decreases and putting it back on the size 11 needles to finish the hat. Will that make the hat too small?
It is not necessary to change needle sizes, I wanted to include a tip on why I did but there was not enough room in the pages!
Garter stitch is naturally a bigger stitch then stockinette. So you will notice up in the gauge section I say 2.5 in garter on 11, and 2.5 in st st on 13’s. It evens the gauge out. It will, if your personal gauge (as everyone holds their yarn at different tensions) is a bit bigger on the 13’s (and it may not be, it may be the same as the garter in 11’s), so in turn if you used 11’s it could possibly make the hat a smidge less deep, and a tiny bit smaller around. That smidge could mean a baby could wear a hat for a little longer before they grew out of it, but maybe not if your gauge is loose! I am a perfectionist. 😀
You do not need to switch to 13’s unless you want it “just so” or unless you knit one on 11’s and it looks wonky on the top, which I doubt it will.
I often don’t switch to smaller needles for cuffs, as many patterns call for. It is “better” but sometimes it just doesn’t matter to me, and the item is well worn, well loved, and just as cute.
So as the well known Elizabeth Z always says, knitters choice! I do believe the over-all fit will be better with the gauge matching on both the stockinette portion as the garter stitch, otherwise I would not have called for it in the pattern, but it is one of those things that you can probably get away with if need be.
I’m not sure I ever “officially” shared the yellow photos of LG in my second test knit of Serendipity, it’s a wee bit deeper then the pink one so has better neck coverage!