First I recommend that you use the JPG format.
300dpi is more adequate.
Black is always a problem especially if you use large areas of black. There have been countless discussions on the forums about this. Search and ye shall find! You need to use a really good image editor such as Adobe Photoshop and spend a great deal of time getting the levels correct. It's no use just banging an image in and then use an automatic adjustment. I spend hours preparing my images and always achieve perfect results. If you don't know how then see this http://www.lynda.com/Photoshop-CS5-tutorials/essenAs for the white edges if you are sure that you got the bleed correct then contact Support with details to get a reprint.
Ken Anderson - The Lulu'ers Professor
I just got a copy of my book in the mail today and there are some things I need to fix but have no idea why they even happened in the first place... which is why I'm here, hoping to get some answers as to how it might be fixed.
Okay, first, it's a graphic novel that has black and white interior. It's the Crown Quarto size. I uploaded 4 pdfs because uploading the original big file didn't work.
I am still not sure why your files are so large. It could be the image file types, or how you placed them on a page (very large images 'Fitted' to a frame remain large as a file).
It just got stuck after several minutes (reaching 10 % or less - I tried many times, through FTP as well as through the publishing wizard). My pages are PNG files at 300 DPI, grayscale. I read here somewhere that it's best to make GIFs with a solid black lineart (for comics) at 600 DPI, which I can easily make, but what's the difference between PNG and GIF here, exactly? I started converting everything to GIFs but I noticed that it takes almost twice as much as PNGs (which look exactly the same. I mean, exactly - pixel by pixel, there's no difference).
I have no idea who told you that here, or where you read it here. It's a long time since I used anything other than jpgs, but as far as I can recall, the 'white' on a GIF is constantly transparent and can be a pain, if for example, you wish to print on a coloured t-shirt. I have never used PNGs. It's not how a file type looks, it's how they work.
300DPI should be OK, and will make your files smaller, too. But use jpgs as Ken suggests.
Okay, now to my problems. First, it came out way too bright. The black isn't really black and you can't even see the bright shades, they're just white. All the grays look really bright. I have another book that wasn't printed at Lulu that is basically the same thing (different comic pages, but part of the same series so same files, basically), and it looks much better. The blacks are great and solid and the grays are perfect as well. What am I doing wrong with my files at Lulu?
It sounds as if you are doing nothing wrong if you are doing the same thing with each book. It sounds like a printing problem.
Another problem is that on several pages there's a margin of about 2mm at the top of the pages. It's more obvious in pages with black backgrounds that go all the way to the edges and bleed. You see a white stripe at the top. I don't understand why it only happens at the top of the pages and not any other side of any other page.
And you do not see that in the PR PDFs? If not then that too could be a printing problem. Printers hate blocks of black! It does sound as if the trimming has not been trimmed at the image edge though after printing, which is not uncommon.
That's strange. I used Lulu specafications for the margins.
Margins with full bleed?
I read somewhere in the forums that making the whole thing one pdf file solves this,
Well it does no harm, and does simplify matters greatly.
but like I said - I couldn't send the file. The only way that would happen is if I make it smaller than 60 MB, which doesn't seem very likely. It's 192 pages.
3 MB per page does sound a lot, but dropping to 300dpi and jpg should lower that a lot.
Re: Images came out too bright & everything got cut wrong (despite proper bleeds).
We don't mind confused.
I'd suggest that you use grayscale JPG or grayscale TIFF.
I've produced hundreds of books here on Lulu without problems.
What I did do many years ago was to create a sample book using all types of images and drawings with the files saved in dfifferent formats and different settings in Photoshop. That way I was able to determine the best settings for printinh with Lulu.
It took a little time to prepare but with the result that I've don't have problems in production.
I've not intention in getting into long discussions about what is right or wrong - I'm just giving advice based on my own experiences printing here and with traditional offset litho printing with book runs in their thousands.
Ken Anderson - The Lulu'ers Professor
I think you're reffering to photographs and stuff like that.
It does not matter what the originals are if they all end up as a digital file. Often they even start life as such. One of my cameras will take up to 15mp, and that is a waste of memory unless you intend to blow the image up to the size of a tennis court. Oh, and everything I have that can take a digital picture uses jpgs. Film photos used to be around 57dpi.
That would make sense to print as JPGs.
It does not matter what is being printed. All the pages get converted to PDF anyway, what does an image become then?
I think I made the mistake of keeping my files grayscale (which is also why they were pretty big) instead of converting to lineart (just black and white, no gray).
It actually does not matter because if you upload full-colour pages to Lulu's Wizard tools and select B&W, it will convert to and print as B&W.
PNGs and GIFs
PNGs were invented to replace GIFs. JPG was come up with, if not to replace those, but as better alternative due to its compression, which is adjustable. That must tell you something?
with lineart actually take way less (yes, even at 600 DPI) than a JPG would.
I do not see how because I am not sure that they compress, but what is in an art file surely does not matter? It is still a file of a certain dimensions and saved as such?
I now realize that I can shrink my pdf by half or more by using PNG or GIF (and it doesn't matter if the white is transparent since this is white paper I'm printing on) at 600 DPI,
There is no need to use 600dpi unless you intend printing an A0 book and you cannot do that here! I create jpg art at 18" x 12" and at 300DPI. At that size because it is hard for most PCs to work on Poster sizes, but they can be printed out at Poster size with no pixelation, and they are..
after I make them black and white and not grayscale. I'm not sure it'll print well at 300 DPI, it might look too pixelated. How will this print in general, though, that I don't know. Each file takes no more than 600KB, most take less, sometimes 200KB even. I checked.
Greyscale is best rather than B&W, you just have to make sure you create the images to that the very light greys will show when printed. As Ken suggests, try some test prints, then set your monitor to match a test print. But even that is no guarantee that Lulu's printers will always print them well! QC can be a bit 'random'. They will print OK at 300DPI, really.
Have you actually printed something like that with JPG?
Indeed, all the time. I have no idea how long Ken as been at it, but I have used PCs for art from the DMP days.
I've printed stuff that is similar to this book but I've used EPS, PNG, BMP, TIFF... never JPG. I just don't see how that would work. At all. Sorry for questioning your suggestions like that, I just don't think your advise is relevant to my book. Of course, I'm also new here and this is my first book at Lulu, so what do I know.
Just try it. What have you got to lose but a few £s or whatever for a Proof? Do a test publication of a few pages. It will cost peanuts, (Just set at Private). However, it sounds as if you have. It may not actually be anything you can do to how you create your file of pages if you are not happy with the results. It could be the paper.
You could possibly cheat and make your pages just a bit oversize? Or just a bit taller. But to be honest, if it did not show up in the PR PDF then it's a trimming/binding error and should be reported to Lulu.
Will Lulu allow me to upload pages that are bigger than 7.565'' x 9.925'' (Crown Quarto format)? I mean, that's what they call "document size" so... I guess not? It's just that if I could make a bigger blead area this won't really be a problem.
Ah! You have already wondered about that.
Actually, we have no idea what results you are expecting from your Proofs because we have not seen them. 
