Ok, I hope some of the experts out there can help me out. I'm using photoshop to make some high quality posters that I'm going to print out using our university printers (very nice, archival paper, etc.), and I want to be sure I'm doing everything I can do ensure the highest quality I can. So this is what happened, I started making these posters with no intent to print them at first, and so I made them 10"x6.67" at like 150 DPI. NOW, I want to print them at 18"x12" and also at the original smaller size. Also in these posters it's pretty much just text and shapes made using the shape tool, some textures, etc. Here are some of the one's I've done up to now to give you an idea of what I'm working with: https://lostindesign1.wordpress.com/ I have a variety of questions: 1. Is it true that if I just go into the current file and change it to 18x12 at 300dpi, it won't actually be that quality? I've heard this is true. 2. Would it be best to make a new file at 18x12, 300dpi, and then import everything from the old file, or simply make them new again? (NOTE: I have no real objection making them new if it will make it nicer, also, there's a lot of things I actually want to change with them so I wouldn't mind starting from scratch). 3. Going off of that question, let's say I make an 18x12, and I want to print a 10x6.67, could I just decrease image size, save it in a printable form, and that won't affect quality? 4. That reminds me, what is the best format to print from? I know not JPG, but maybe TIFF? not really sure here. 4. When using these shapes and texts, should I rasterize them once I'm ready to print, or does that not matter? Or is there something else I should be doing? I'm confused about this whole rasterizing thing. Sorry for the boatload of random questions, I just want to be sure I'm getting high quality stuff here when I print these, as I'm going to be giving some as gifts and I just want them to look nice around my apartment. Thanks to everyone who helps out!