Do you make hats with crown sizes? It looks like one size only, there are different brim widths??? The hat you offer is over an inch to big for me.

I am not the seller, however I do have the hat and love it. That being said I use the ribbon to tie it and keep it on my head. The hat does come folded as well. The hat is made of straw and I just used a warm iron to "iron" out the folds, it was really no big deal.

What is the diameter of the 17cm hat?

I purchased the largest brim they offered. It is 20" in diameter. Good sundress hat. Decent quality.

What does brim: 12cm mean? it’s no known hat size. my small head is 21 inches in diameter.its the crown that matters. what size is the crown?

The crown seems the same but the brim is very wide. I'm wearing it with a colonial costume and will order the 10 cm brim.

Could you trim the brim without ruining the straw? looking for a gibson girl boater a shallow crown and a thinner brim.

Yes, I do believe that you could. The straw is pressed flat then placed on a sewing machine and stitched round and round about. If you took a seam ripper and slowly undid the seam to stop at the size that you wanted, it should be ok. I would use a clear glue to go about the seam where you decide to stop to assist in securing it.