Custom field length not correct

My product description field width is set to 90, but I have custom fields there which don’t recognize it. So it over-writes the next field (product code).

I have used this code to display the custom fields (as instructed) in the product description field such as greeting card texts:
return (new CArrayField(“table”,”meta”,””))->GetFormattedMetaData();

How to get the custom field to do a so called line break </br> when it reaches the end of the product description width which is set to 90?

Thank you for your help!

Mart