I cannot get a gemwin to size consistently with what I put in the message window. default seems to be 500x500, I try 1920x1080 with no success (though for some reason this worked momentarily when I changed the message window to 720x480 - the gemwin went 1920x1080, but just once)

the gemwin activate error is 0

any thoughts? thanks!

are you using messages in the form of [dimen xxxx xxxx[ ?

You must re-create the window after sending it a new [dimen( message.

In your case:
-Send message [dimen 1920 1080( to [gemwin]
-Send message [create( to [gemwin]

If you already have the [gemwin] open, you must destroy it and re-create it for the [dimen( message to take effect.

thanks for your help.

For some reason, the solution lay in clicking on the message box with [dimen 1920 1080( before creating the gemwin...I had assumed that clicking on the [create( message box would read the dimen information automatically if it was indicated and linked.

is it standard practice to click on the dimen before the create message box?

I am happy I can now work in a larger format!

yes you have to click the dimen message before creating the gemwin

I often set up my gemwin with a bunch of messages in one box:

[dimen 640 480, lighting 1, create, 1[

One click sets the size, lighting, creates the window and starts rendering.

Nestor's sollution is a good one. You can also put a [loadbang] on your dimen message so it gets sent automatically when you load the patch.