Application of Gst rates

There is clarification of CBIC on this .

If intellectual property rights are transferred (say book content send for printing) = then it is treated as "Supply of Service" 

BUT 

if printing of logo etc on T-Shirts , Cups , bags etc then it is treated as "Supply of Goods" 

In your case, 

predominant supply is that of goods and printing is as ancillary services so it is treated as Supply of Goods and rate of such goods is applicable .