Step 5 Now change the image resolution to 150dpi and the height to a maximum of 25cm; this will make the subsequent Illustrator file smaller. Save it as a PSD.
Step 6 Open the PSD file in Illustrator and use the ‘Convert Photoshop layers to objects’ option. Now all your layers are in Illustrator’s Layers panel.
Step 7 Set the document up as a portrait A4 page, then save it as an Illustrator document. You can save it as a PDF instead to reduce the file size and stop your hard disk from overflowing.