The shape of the 223 is similar to that of the 224 but the hairs are different. The 222 is a select goat hair like that of the 217 but it comes to a more precise, smaller, less fluffy, rounded tip. There are pictures of them all on macocsmetics.com.
I've heard a lot of artists say that the 223 is their all time fave blending brush and I'm getting mine when we re-launch it. I'm also buying the 222 this week. The 217 is my favorite blending brush and it's a more precise version of that
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