The Cyanotype Negative Linearizer prepares digital photographs for contact printing onto UV-sensitive cyanotype and alternative photographic emulsions. It inverts the image into a contact negative, applies custom gamma transfer curves to counter emulsion shadow compression, and renders optional step wedges for exposure calibration.

### Why Digital Negatives Need Curve Linearization Unlike modern multi-grade silver gelatin papers that exhibit linear tonal gradations, alternative chemical processes like classic cyanotype (potassium ferricyanide and ferric ammonium citrate) or Van Dyke brown prints have steep, non-linear characteristic curves (H&D curves). Shadows block up rapidly, while highlight details remain faint without substantial exposure. Printing an uncalibrated negative produces muddy midtones and lost shadow separation. Applying a custom non-linear curve expands shadow details and protects delicate highlights.

### Chemistry & UV Tint Selection - **Chemistry Options**: Classic cyanotype formula, New Cyanotype (Mike Ware formula with higher contrast), or Van Dyke brown. - **UV Blocking Tints**: Amber, green, or clear base tints. Colored inkjet ink absorbs UV actinic light during exposure under sunlamps or direct sunlight. - **Calibration Step Wedge**: Renders a 60-pixel step wedge margin strip alongside your image to test UV exposure timing on test strips before exposing full art prints.

### Worked Example Workflow 1. Upload an 8-bit black-and-white or color portrait. 2. Select Classic Cyanotype chemistry with an Amber UV-blocking base tint. 3. Set Shadow Boost to 30% and Highlight Compensation to 20% to prevent deep darks from clipping during solar exposure. 4. Toggle the Step Wedge on to include a 10-step reference strip on the right border. 5. Export the linearized negative and print it onto transparency film (such as Pictorico OHP) with an inkjet printer for darkroom contact printing.

### Processing & Privacy Pixel inversion, contrast curve remapping, UV tinting, and step-wedge generation execute strictly on your device using the HTML5 Canvas 2D API. Your original photographs and high-resolution negatives are never uploaded to any cloud server.