Hi,
In your case the best solution is to use the options and not the custom fields.
Thanks to the options, you can restrict them to a desired product.
So you have to create two characteristics, one named "Running fabric" and the other one "Microfiber fabric".
Add the desired values to each characteristic.
Then create two option products, the first one "Running fabric" and select the "Running fabric" characteristic, do the same thing with the microfiber one.
And finally add to your main product the option "Running fabric" if it's a running fabric, etc.
Here is doc for characteristics:
www.hikashop.com/support/support/documen...html#characteristics
And here doc for options:
www.hikashop.com/support/support/documen...ct-form.html#options