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To make object, stroke, and fill visible in print, you have to enable them from expand menu. Also, if you want gradient mesh, check that option, too. From expand appearance, you have to select brushes and fill, again for exporting in print.
If you want to print a file for a poster, then your color mode should be CMYK. And if you're going to use your file for the web, color mode will be RGB.
When you wanted a file to print, which contains shadow or transparency, you have to use special printing options. From the preset, change image size and enable transparency. In PNG format, the background will not include in saving so that the print will be according to like it.
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