Oh I've always used steam to set my seams. Never had a problem. Now i don't add water to my iron so sometimes I remember to spritz with water and then press.

I use steam and starch together. I think the steam seeps the starch into the fibers.

I think this is absolutely probable. I've noticed that if I spray starch on fabric, then spritz water on the starch, then iron, I *never* get flaking.

I like the flat seams I get, so I press with steam.

Thank you for mentioning this. I have been using a dry iron and a spritz bottle of water. Maybe it isn't the best thing to do. I will try dry ironing as I work on blocks to compare.

As people have said there is the possibility of distortion with some areas stretching or remaining straight. Personally I dry iron for most pieces but have been known to steam those thick seams especially where you have a bunch of points.
Try yourself using steam and see if you like it. We live in a free country.

Fascinating! Thanks for all the replies. It's good to question the way I do things from time to time. Given that I pre-wash, shrinkage shouldn't be a problem, so I'm going to start to use steam. However, I take the point about distortion of HSTs and small pieces in general, so I'll maybe not do so all the time.

Thanks for this tip, Barb - will definitely try it, especially on those difficult centre fold lines. I've had trouble with those recently, trying to use up fabrics that have been sitting in a drawer for too long.

The big pro steam presses don't iron. They press with top or bottom steam or both. If you wanted to make sure nothing distorted, you put pins in it or found another way to hold the shape before steaming.

I suppose if you want to steam HSTs - you can pin them and blast steam from above the pins and don't touch them with the iron. Wait until dry and cool before unpinning.

I use steam all the time because I prefer it. I do make an exception, however, when I'm working with bias edges as they are so easy to stretch. Steam away!