Hi,
I got a few Marshalltown flat trowels from about 12" x 4" to 16" x 4" I've used for a bit of cement work. Â Â I thought (assumed? = prone to being mistaken) that they were too thick/stiff than what would be right for plastering work. A Marshalltown representative I asked about it though told me their cement trowels and plastering trowels are one and the same, that their catalog shows them all under the cement heading, and the only difference in which one you use is a matter of personal preference. So I guess I already have the trowels I need.
The rep also said she found a lot of plasterers prefer a 3" wide trowel, but many use a 4" wide too. I guess what I got is close enough to have a go at a bit of skim coating and see what happens.