Set your artwork to RGB Black (0/0/0) and ensure all fonts are outlined and at least 6 pt in size. Avoid sharp corners, solid areas with knockout text, and vertical lines longer than 1.00″, and make sure all lines are at least 0.65 pt thick. Before exporting, remove all non-artwork layers and save your file as a PDF/X-1a.
* may appear blank until opened in Adobe software. Please do not save your design in the 'artwork guidelines' group layer or it will not print.