Edit Form UI

Hello there,

I created a UDF for the Item Master Data. The field is 100 Alphanumeric. When I open the Item Master Data form the field is the separate windows when I press Edit Form UI I can drag and drop the field in the main area (under tab Stock Data) problem is that the text field is a squared field and I would like to be like a classic text field (like the Description just to give you an idea)

I don't see a way to do it.. I read in on manual that you can't make smaller the field (so I assumed that you can make it larger)

Any suggestion?

Thank you