"Missing required value for mandatory field: itemType"

I have about 15 surfboard bags that I need to add to my Netsuite store.  Each bag has 5 different sizes (matrix items).  I am trying for the first time to create a csv file to import all these matrix items.  I read on one thread that the parent item needs to exist in Netsuite before you can add the children using the import feature.  So I created the parent with one child manually in Netsuite.  Then I created a csv file with the following headings in the file:

External ID, Item Name/Number, Display Name/Code, Sales Description, Store Description, Detailed Description, Size, Matrix Type,  Subitem of, Price Level, Price, Vendor Name/Code, Out Of Stock Message, Taxable, Item Weight, Drop Ship Item, Manufacturer Part Number, Purchase Price, Item Display Thumbnail, Item Display Image, Display in Web Site, Site Category, Item Options, Product Category,