Marketpress product upload from CSV

Marketpress has the ability for each product to have a variation.

A shop I am trying t upload has products in different pack sizes (e.g. 10, 25, 100) and this is ideal for variations.

I would like to upload via csv, but the example csv file does not have a variation example.

I have tried the obvious, i.e. using the same product title, but this just creates an extra product.

Is this not a feature of the upload to allow multiple product attributes, or am I missing something?