## Custom Curve Creation with QTP-Pro ### Partitioning One of the more powerful features of QuadToneProfiler-Pro is the custom curve creation program that will generate new .quad files for any combination of gray or color inks through a process known as “partitioning.” The QTR curve creation program uses settings manually calculated and entered into the ink descriptor text file to determine the partitions. I created a new partitioning algorithm for QuadToneProfiler-Pro that is much different from the traditional QTR curve creation program. The Custom Curve Creation system revolves around measurements of each step from the whole ink separation image, rather than only using the individual ink limit and manually calculated cross-over point for each channel. Having measurements from each step allows the profiling application to re-interpolate the full scale of the inks at any ink limit and automatically calculate the cross-over points to partition the inks. The initial quad curve is automatically created and updated in real-time when editing the overall ink limits and each channel’s starting and ending overlap settings. An approximate correction curve is automatically calculated from the rescaled measurements from the densest ink and applied to the initial curve to adjust for the non-linear density increase in the printer’s native output. You can then manually edit the base quad curve with a boost or gamma adjustment for all channels and manually edit each curve on an ink-by-ink basis. ### Overview of the Custom QTP Profiling Workflow - Create, print, and measure the Ink Separation Image - Create the custom base gray and toning curves from the separation image measurement files - Linearize the base gray and color toner curves - Blend gray and toner curves into .qtp profile components - Linearize and measure blended toner components (suggested, but optional) - Create the .qtp file from components - Use the .qtp file to preview the color blend and make the quad curves for printing. ### Detailed instructions for each step 1. [[Creating the Ink Separation Image]] 2. [[Creating the Base Gray Curve]] 3. [[Creating the Toning Curve Components]] 4. [[Grayscale Linearization]] 5. [[Linearizing the Color Toning Curves]] 6. [[Blending the Base Gray and Toner Curves]] 7. [[Linearize the Blended Curves]] 8. [[Creating the .QTP File]]