Please submit your files in .PNG format and 300 dpi in resolution. Make sure they are of actual size.
Kindly rename your files as: Print Name_Type of Paper_Actual Print Size_No. of (12"x18") Sheets
Example: Print1_C2S_4x6_2sheets
Note that what you put in the quantity box is the number of 12"x18" sheets and NOT the number of individual prints.
Printed outputs are in CMYK so please take note of this when submitting your designs/files. As PNG is RGB by default, try to preview your work in CMYK mode to set your expectations. Actual product colors may also vary from colors shown on your monitor.