How can I change the input type from number to text?

Several questions were added as "number" and must now be changed to "text" to be able to accept letters as well. Can this be done (so I can keep the question text and textbox size as-is) or does the whole form need to be recreated? Also, if I have to do this manually, it seems that the textbox width property has no function - no matter what I enter there the width remains the same.

It is not possible to change the type and retain its properties. You would have to delete the field, create a new text field and configure its properties. 

And when I do that, the textbox size property appears to have no impact on the appearance of the textbox (as shown in the screenshot). So now I need to create a completely new form? It seems that by launching the Advanced Editor I have lost the ability to change the textbox size of an individual textbox (I can still change the size of number or email boxes though).

When you change the width of the Short text entry field, the size of the field should also be changed. Please see the screenshot below:

If the width is not displayed as per the size set in the field properties, the theme applied to the form might be overriding the properties. You may try applying the default theme from the Themes section in the Form Designer or try reducing the width of the field from the Advanced form designer.

Hope this information helps! 

Right, the width is not displayed as per the size set in the field properties.

Here is the workaround that seems to have fixed things - I applied a new theme then returned to the previous theme I was using.

This seems to have broken the hold that the Advanced Designer had taken on the form (and I lose all of the modifications made with it). Unfortunately, the Textbox and Textarea Width item in the Advanced Designer is a global setting and I wanted to change the width of specific boxes, not all of them on my form - a feature which appears to only be available using the basic tools and only if you stay away from the Advanced Designer. Bummer, but at least I don't have to completely start from scratch.

Thanks.

If you need to restore the form to an earlier version, you may revert it from the form revision history by following the guide below:

https://www.jotform.com/help/294-How-to-View-Form-Revision-History

The width of the specific boxes can be changed by injecting custom CSS code to the form. You may access the CSS code editor from the Advanced Form Designer. Double-click on the field that you want to change the width so that the field ID will be displayed in the CSS editor and then change the width as per your requirement. Please see the video tutorial that can help you with this,

https://www.jotform.com/form-designer/tuts/episode4/

The following CSS code might also help you in changing the width of the field. You may also get the field ID from the field properties by following the guide How-to-Find-Field-IDs-and-Names?

#field_ID {

width: 200px;

}

Hope this information helps!