It is reccomended that B&W images are not sent in as Greyscale, but mine were and have printed pretty good alongside RGB colour images. the colour images are very accurate to my fully calibrated screen. 

I know this does not help your question, but I am getting the impression from reading the forum that this whole set up is pretty hit and miss.

Do not, and I repeat, do not convert your pictures to CYMK.  You have interpreted something wrong it you think that is what Blurb is telling you.

AdobeRBG is much closer to what you need than CYMK, but your photos should be in sRGB before submitting your book.

A computer does not know the difference between a color or b&w image using sRGB in a jpg format.  White and black are just colors, like any other color.

Mike

I had not seen these instructions before.  They are specific to B&W.  Unless something has changed, do not convert color photos to CYMK. 

The linked instructions also use InDesign and dump a pdf file.  Anybody know if you should convert to CYMK if only using jpgs in BookSmart?  What about full bleed jpgs from photoshop?

The first post to this thread implies he converted his color photos as well as his B&W’s.

Mike

Tony is correct. The best practices outlined here  (http://forums.blurb.com/forums/4/topics/7020) are for PDF to Book only. That said, let’s separate best practices in preparing B&W images for digital offset (Blurb books on the HP Indigo press) from color management.

1. Best practices when preparing B&W images for use in BookSmart
(for PDF to book look here)

The biggest challenge in printing B&W images in a 4-color process is the potential for the introduction of a color cast. A color cast is caused when the color space is converted down from the much larger RGB color spaces (sRGB, AdobeRGB, ProPhoto, etc) to CMYK. This is the case in any four-color process. There is also an accepted amoount of color drift within the digital offset presses. This is slight and must meet the acceptable delta as outlined by HP, but while most would never notice a slight shift in Cyan by three in a color image, it i smore noticeable in  black and white images.

Ok, so what to do? The best thing you can do is to be sure there is no underlying color cast in your images prior to importing to Blurb BookSmart. Here’s how:

1. We recommend to open all of your images in Photoshop and run them through the ‘Black & White’ adjustment filter.
2. You’ll find this option under the menu item ‘Image > Adjustments > Black & White’.
3. This will pop-up a dialog with many ways to ‘tweak’ this. I usually just accept the default settings and press ‘OK’ , but there are Adobe tutorials to enjoy if you’d like more detail there.
4. This will remove any color cast from your image that may exist even if it is not visible on screen.

I would hate to disgree with Blurb Staff but I suggest that you read the following post http://forums.blurb.com/forums/10/topics/8249#posts-35099 

I worked on this primarily for PDF to book but I don’t see why it shouldn’t work for Booksmart. It gets around the inherent problems of getting good neutrals with the 4 colour process and still gives good gradation. In the end the only real answer is to do a small test book and see what gives you the images that you like best.