Scan the image through Adobe Photoshop. It is recommended you scan it in high resolution (300dpi), so it will be easier to trace small details. In order to have a smaller file size, select greyscale colour mode in the scanner settings. When finished, save the image as a JPEG file, and select Maximum quality of 12 in the JPEG image options. Select Image > Adjustments > Brightness/Contrast to increase the image’s contrast if needed.
In Adobe Illustrator, Select File > New or Ctrl/Cmd + N and create a new document, name it, and select A4 size, portrait orientation. For printing purposes, we will select the CMYK colour mode. Select File > Place and place your sketch file in the document.
In the Layers palette, change the layer type to Template in the expanded options. Name the layer ‘Template’. Create a new layer. This is the layer we’ll start working on. In order to have the full control, try to separate your artwork in layers. Don’t forget, it’s very important to name the layers, and it really helps when you are working in complex projects with lots of layers.