Linearization? Have you linearized the tonal output on your 4880? You will need a transmissive densitometer. For anyone here that would like to know what tonal values you have on your film, you can output a tonal ramp from 1,2,5,10,15, 20,30,40,50,60,70,80,85,90,95,98,99% at the halftone count you use and the angle that you use on the film you use. Send it to Murakami along with contact information and I will give you a call to tell you what you are actually outputting tonal percentage wise. With Wasatch we can then enter this and Wasatch will curve the output so that you get true tonal readings on your film. I need a 1/2" square of each tonal value. Typically the unlinearized tonal value on film is +10-20%. So a 50% is actually 70 and at 80-85 it goes solid black. With linearization we can get more of the upper tonal values as well as precise lower tonal values that prevent a noticable end point. Also in Wasatch there an interesting feature that lets you combine halftones and stochastic dots. Stochastic dot below 10-15% is random and won't sawtooth or form moire as easily. Wasatch also has the tonal ramp target I describe above in the linearization section that you can use to print out.
Once the film is linearized there is still dot gain during the print. Wasatch has two curve functions, one for film and the next for the press. The same ramp can be imaged and then printed. Note that this second linearization is shirt specific. You will get better results on a high singles shirt with a tight weave vs an inexpensive light weight white promo shirt. the fabric, the baseplate all affect the tonals printed. So this is a subjective area where you can adjust the print curve if you want, or not. The second press linearization can sometimes print too light on a black shirt, yet be crisp and sharp on a white shirt. So it is possible to have multiple second linearizations for various print types, and it can be determined with a relfective densitometer or just using your eye to control dot gain. Linearization is simply a way to control dot gain with the rip.
Murakami
745 Monterey Pass Road
Monterey Park, CA
91754
