             let data = transformer!.transformedValue(attributeValue) as NSData
             
             // convert to string (for JSON export)
-            return data.base64EncodedStringWithOptions(NSDataBase64EncodingOptions.Encoding64CharacterLineLength)
+            return data.base64EncodedStringWithOptions(NSDataBase64EncodingOptions.allZeros)
         }
         
         return nil

                let transformer = NSValueTransformer(forName: NSKeyedUnarchiveFromDataTransformerName)!
                
                // unarchive
                return transformer.transformedValue(jsonValue)
            }
            
            // custom transformer
            let transformer = NSValueTransformer(forName: valueTransformerName!)!
            
            // convert to original type
            return transformer.reverseTransformedValue(jsonValue)
        }
        
        return nil

                
            case "NSData":
                let data = attributeValue as NSData
                return data.base64EncodedStringWithOptions(NSDataBase64EncodingOptions.allZeros)
                
            default:
                return nil
