How do I enlarge the image on Google Docs to make it fill the entire doc?
I had an image of the cover of a book I was reading on my Google Docs and was trying to make it look like it was the background, but every time I tried to make the image bigger, half of the image disappeared.
There is no way to add a background image at this time in Docs. That isn't a feature that Docs currently supports. The workaround is to put your text into a text box via Insert > Drawing and set up the your background image with a high transparency to layer over it.
How to Add a Text Box to an Image in Google Docs
Paste or upload the image to your document.
Click on the image to select it.
Adjust the transparency by going to Image options > Transparency and moving the slider as needed.
Copy the image by clicking on it and pressing Ctrl/Cmd + C.
Go to Insert > Drawing.
Paste the image (Ctrl/Cmd V) in the Drawing application.
Select the Text tool and drag the text box to wherever you want it over the image, resizing it as needed.
Type in the text you want to add, using the font of your choice.
Select the blue Save & Close button.
To help influence future feature changes or additions in Docs, I encourage you to provide feedback about this directly to the Docs team by following these steps:
Open a document.
Click Help > Report a problem.
Enter your feedback.
Although the product team is unable to respond to individual users directly, they review this feedback regularly and use it to help improve the product over time. Google doesn't check the help forums for user feedback, so it's important that you use the in-product tool. The more users who request this capability via in-product feedback, the greater the chances are of the team considering it.