How To Get Optimal Photo Print Quality With Lulu.com
By Chongchen Saelee
Lulu.com is a book self-publishing service. You can print your own novel, comic book, photography book, calendar, etc. But each type of book will require a decent amount of technical skill to physically create a presentable product. When dealing with color printing, you will definitely encounter some road bumps. So I’ll share with you what I did to get optimal results for your printed photo book when using Lulu.com.
Lulu.com outsources their print jobs to many printers all over the world. Sometimes it depends on what type of print job is required, sometimes it depends on vicinity to the customer. So the print quality of your books will vary. If your project gets sent to an offset printer, you may not like how the color prints turn out due to lower resolution and half-toning.
But Lulu.com acquired partners with newer industrial size inkjets which can print at higher quality and for cheaper. And in the digital age, with all these high resolution digital images popping up, it only makes sense to use the printing technology that is capable of printing at higher resolutions.
1. Use high resolution quality images to begin with. That means no upscaling, no blurry taken photos, etc. It might look sharp on a computer screen, but once it’s printed with ink on paper, the inks tend to bleed together and what you thought was a sharp image will end up looking blurry on paper. I observe the best quality photos in print are the ones that were already in focus and tack sharp out of the camera. You can digitally sharpen your photos for print, but I find sharpening halo and artifacts still show up in print, if not makes it more noticeable.
2. Although Lulu.com suggests general and minimal resolution of 300dpi for colored images and photos, I find the print quality to be still soft and noticeable. I recommend using a minimum of 600dpi for any photos or even black and white line drawings. That means you must convert your resolution correctly. In Photoshop, you’d be modifying the “Document Size” proportionally and not the “Image Size”.
3. Use optical tricks like color contrast to give the illusion of sharp edges. This, of course, must be done at the photo-taking process. You can attempt to do this in the photo-post-processing step, but it’d be hard to achieve seamlessly.
4. Only use the size of the final image you intend for the book. Do not do any resizing or scaling inside your layout software, such as Adobe InDesign or Quark Express. Resize your images before placing them into your document.
5. Save your high quality images as JPEGs and not BMPs. If you’re daring, you may even save them as PNGs. But always try to avoid image compression, even with a lossy format such as JPEG. The idea is if you’re going to be putting hundreds of high resolution images into your document, you need them all to fit the PDF file limit size of 2GB. And you don’t get to use the full 2GB for storage either, it’s more like 1.5GB.
I noticed even printing at high resolution like 600dpi, the printer will still apply some halftoning. So make sure your images are formatted correctly and have sufficient “sharpness”, otherwise that halftoning process will “remove” pixel data and your printed images might look soft.
Hope this helps. And if all fails, you will have to order your proofs and go through the trial-and-error process until it looks just right. But hopefully, through my own experience and expenditures, I can save you a few steps and few dollars.