All books were printed on creme paper and the first to arrive was a Createspace proof from the USA (middle book in image). Blogs had already warned me that the creme paper was the most yellow but without any comparison I was more than satisfied with the end product.
Then came the Ingram Spark version printed by Lightning Source in the UK (the bottom book). This was thinner than Createspace and less yellow but had a disconcerting wavyness to it which can still be seen despite pressing under weight.
Finally the more expensive heavy weighted paper from a POD company in the UK (top book). This was altogether the best product and the creme paper was the lightest in colour.
I had read that the wavyness of the Lightning Source book was due to the heat from thermal digital printing and on closer inspection I could see an embossed sheen on the print and the images. This was not the case on the other two books which must use a different print method. The upside was that the images were much more crisp. Even though I am using Creatspace to supply Amazon UK it will be the Lightning Source version that is most likely supplied in the UK as Createspace outsource production here.
The image above shows the print and the colour of the creme paper more clearly. The book are in the same order top to bottom as the previous image.