By default with index seps your not really creating any terciary colors by blending primary colors. Also you must have a good working Idea of how to predict area of coverage times the number of imprints to mix the correct amount of ink. Even if your very close your not going to get it exactly right very often. That means over time your going to generate a HUGE number of small containers with pms colors you will likely never use again. Even if you do need it again you will likely have to mix enough to use for that job anyway hence more mixing. With Simulated process you get a more forgiving registration, you use the same basic 9 colors again and again so if you mix a little to much no worries your going to use it again in a day or two anyway. The vibrancey is every bit as good and in many cases better. You will have a much broader range of colors to use in a design with out exceeding 8-10 colors in most cases and most importantly after you do this process for a while you will begin to get very predictable results. When you can predict whats going to happen on the press every time you begin to exponentially improve your skills from start to finish while maintaining an acceptable cost factor. I worked as a consultant to this industry for a long time and I can testify that several shops using primarily index seps had a lot of waste ink. One shop I vivited donated a truckload of waste ink a year to the prison print shop. You tell me what a truck load of ink cost them?
Lastly with Simulated process predictably engineering the colors to print wet on wet provides for a broad range of terciary colors you would not otherwise get with index or flat spot colors. Purple or violets, oranges, greens, greys and browns in every shade.
By the way I've been doing simulated process seps since before Photoshop would recognized alpha channels as such. There are some automated actions and stand alone programs that will make it easy for you. Just be smart, and make the process easy and cost effective for yourself if your not familiar with photoshop. (older versions of photosho pre-v6 have the best alpha channel previews).
good post Dave. I'm not trying to argue but i'd like to discuss this further and hopefully inform myself more.
"By default with index seps your not really creating any terciary colors by blending primary colors."
You can easily create tertiary colors using index method just as with simulated process. I don't see why you'd say you can't.
here's a good article on ink management software.
Bring Order to Your Inkroom with Ink-Management Software | ScreenWeb | screenweb.com
"With Simulated process you get a more forgiving registration, you use the same basic 9 colors again and again"
so you are always using the same colors for all different designs?... this doesn't make any sense if you're designs require specific colors. you don't do Pantone matching for your clients?
Dave, don't get me wrong.. i'm not trying to say one method is better then the other, they are both viable and have their pros and cons. I've been doing index for the past several years but have been doing simulated process allot longer and often use both techniques together.
from my experience Simulated process is much more forgiving on press. Index can produce more colors on press with fewer screens but require tight registration, prime setup and exact color matching for ideal results... if registration is off a bit it's noticeable.. if the colors aren't matched exactly it can drastically effect your print. Index tends to produce a more accurate reproduction then simulated process but requires more skill on press.
"The vibrancey is every bit as good and in many cases better."
how so? they're both plastisol inks deposited the same way just using different patterns. I think the vibrancy would depend more on the ink color and opacity more so then separation method.