Last month (Nov. 17th 2012) Shapeways changed over to new colors for their Strong Flexible material. I ordered one of my models with one of the new colors to evaluate it, since the change would effect some models I sell in my Shapeways shop. I had to make some changes to my model options due to the new material, and wanted to share my results.
The actual material here is the Strong White Flexible. Shapeways has just changed the options for some of the colors and processing for this material. For white and black there is no change. If you want a different color, e.g. blue or red, then you can only get them in the polished. The polished processing involves taking a SWF (Strong White Flexible) model and putting it in a Vibrating drum with abrasive material. This grinds off the outer surface of the model to make it smoother. The new colors use a new dying process at Shapeways. This is performed after the polishing. The new dyes are meant to give a more uniform and vibrant colors.
My concern was that you could now only get colors in the SWF material if you also get the material polished (unless you want black or white). Polishing sands away the outer surface and changes the dimensions of your model. For many models removing a little thickness is not a problem, and the polishing can improve the appearance. However for puzzles and other models that depend on a tight or friction fit between parts, this could be a problem.
I ordered my model "SOMA's Revenge
" in the new PBSF (Polished Blue Strong and Flexible). For this puzzle the parts slide inside other parts with a friction fit. If to much material is ground away the parts will fit to loose. When I received my model in the new PBSF I put some parts together and found they were indeed to loose. I measured the rods in the model, and compared them to one in the White Strong Flexible material. What I found is that the diameter of the rods were about 0.15mm less in the polished material.
I decided not to make my puzzle available in the new colors, as the parts would fit to loosely. They fit nicely if they are ordered in white or black. I have also used enamel spray paint for models on my puzzles, and they look better than dying, and this does not change the fit of the parts (due to the porous nature of WSF).
As far as the appearance of the colors, they look nice. They give a deeper and more uniform color. However the blue looks more like purple in my opinion.
I have attached some pictures of the blue parts I ordered of my SOMA's Revenge
puzzle. They look even more purple in person. I have one blue part beside a part in WSF where you can see the difference in the parts thickness if you look carefully.
Post your pictures of your models that you order from Shapeways in the new colors here and let others know your results.