When you print a receipt in 

Receipt Margins issue

By changing the margins in the print preview page you can see how the receipt size is changed:

Scale:

 Changing the scale will lead to the changed size information on one paper:

Wrong Paper Size

Occasionally, Google Chrome will not pick up on your default receipt printer papersize settings and you will have to set it to the proper receipt paper size one time in the browser when printing.  

To do this in Chrome, you hit the "More Settings" button in the print preview and select the correct paper size. 

The below screenshot will allow for you to have a little more guidance:

Receipt font size is too small

Sometimes it can happen that the printed receipt font size is being printed smaller than expected.

First of all, receipt template has a  setting for the font size. Navigate to Receipt Template settings->Font Size

The Chrome print preview page has some tools that can help with better receipt size: