Direction does not reverse the book
A right-to-left comic normally still stores its reading pages in sequence. Choosing right-to-left here changes the PDF viewer preference and the ComicInfo Manga flag. It also places the right half first when a landscape image is split. It does not reverse the complete source-page list.
Automatic direction reads the existing YesAndRightToLeft Manga value; otherwise it uses left-to-right. Override that choice when the source metadata is wrong. PDF viewers and comic readers can interpret direction preferences differently, so verify the first few transitions in the application you plan to use.
Review every automatically split image
The spread option divides every selected image that is wider than tall at its horizontal center. It does not recognize panels, binding gutters or whether a wide cover should stay intact. Odd widths are handled without dropping pixels: a 321-pixel image becomes a 160-pixel left half and a 161-pixel right half.
Use the prepared-image preview to check speech bubbles and artwork at the center. If a particular cover or experimental layout should remain whole, prepare that selection separately with splitting disabled. The tool does not guess a safer crop or recover artwork already hidden in a scanned binding gutter.
Understand what the screen preset changes
The grayscale screen preset fits each prepared image within 1200 × 1600 pixels, preserving aspect ratio and never upscaling. Transparency is flattened onto white, colors become grayscale and transformed pages are stored as new PNG images. This is a generic preparation preset rather than a simulation of a named e-ink device.
Small lettering can become less legible after downscaling, and color-coded artwork can lose distinctions in grayscale. Compare a text-heavy page at normal reading size before processing a large archive. Keep original color and resolution when those details matter. Display contrast, refresh behavior, device import and physical screen appearance cannot be certified by a browser preview.