This add-on works with fluid width areas only. Not fixed widths.
 
Find this package in the list of packages awaiting installation.

Installation:
1. Add the main 'elastic_text' folder to your Concrete5 site 'packages' folder.
2.'Sign In' to your site as administrator.
3. In your 'Dashboard' find 'Extend concrete5' and click 'Install'.
4. Find 'Elastic Text' in the list of packages awaiting installation & click to install.

Usage:
1.'Sign In' to your site and click 'Edit' in the c5 toolbar.
2. Choose an area to 'Add Block'
3. Choose 'Elastic Text'
4. Input options and click 'Add'
5. Re-size your browser window to test.

Options:
 Font Size - sets the scale as a percentage of the container width.
 Line Height- sets the Css line height as a multiple of Font Size.
 Max Font Size - in pixels.
 Min Font Size - in pixels.
 Inline Css - to force Css designs.  ie: in stacks.

6. If you return to the form in 'Edit' mode you can see the block's unique Css Id.