Color calibration and RIP

I've got a conclusion about color calibration and RIP.

1. Make my printing data by Adobe RGB.

2. Google iPhone case printing shops which use 3D sublimation.

3. Ask them for print my data on their sublimation film and send the film me.

The reason:

My top priority is to avoid poor dither dots. It is accomplished by 6-color printer. Therefore I must use 6-color printer when I print picture.

Dye-sub ink available 6-color printer is not low end. Its color calibration is not easy and requires expensive devices, I think. Moreover, I may fail at all.

I can avoid the cost and risk by subcontracting to iPhone case printing shops. The price will be around $50 for 5 pcs A4 sheet, I suppose. I'll try enough by my low end printer, and use the iPhone case printing shop for final product.