How do i customize an invoice so i can have a work description diaglog area that is not apart of the field lines.

We can customize the invoice form through the Custom Form Styles page, cortekair.

We can add a custom field for the work description of your invoice form. Let me guide you with these steps:

Before doing so, we'll need to turn on the Custom fields option first. Here's how:

1. Click the Gear icon, and then select Account and Settings.
2. Go to the Sales form.
3. Click the pencil (edit) icon on the Sales form content section.
4. Enter a description under the Name field.
5. Tick Internal beside the customised field.
6. Click Save, and then Done.

Afterward, you're good to a custom field on the invoice form. 

1. In the Custom form styles page, click Edit on the invoice form.
2. Go to the Content tab.
3. Select where you want to add the field either in the Header or Footer.
4. Scroll down and click + Custom field.
5. Tick the customised field.
6. Click Done.

I've also added this article if you want to let your customers pay the invoices online: Create an invoice your customer can pay online.

Don't hesitate to tag my name if you still have other concerns. I'm here to help you!