thanks, I'll give it a whirl!
EDIT...you gave me a lot of ideas to compare things...what I ended up doing was:
Copying the eq2ui_fonts.xml file to my custom folder and instead of making a new ChatInput2 font, I told it to make the existing ChatInput font size 18.
However, while that did make the chat input font size bigger, it kinda bounced up and down in the text entry line while you typed...
So, I went into Insom's custom eq2ui_mainhud_mainchat.xml and changed this line:
<Textbox Color="#F0F0F0" Cursor="/Cursor.Text" Location="18,147" Name="ChatInput" PackLocation="left,bottom" PackLocationProp="0018/0001,-025/0001" PackSize="absolute" PackSizeProp="0024/0001,xxxx/xxxx" ScrollExtent="362,18" Size="362,18" Style="chat_textbox" />
by changing Location up by 2 pixels to "18,145" and the ScrollExtent and Size to "362,20" to make the text entry line taller a bit...and that fixed the hopping text thing.
The little chat bubble icon for the default chatmode picker sits a bit high on its button, but I can live with that.
Basically, this accomplished the goal while changing as little as possible. Your example was a great help!