I cannot find a crosshatch style LoRa for Flux, so I created one 😹.

You will probably need to use the word "drawing" or "sketch" for the LoRA to take effect, and if you want black and white, you should use "black and white drawing/sketch". The word "crosshatch" is probably not required, but use it to indicate your intentions clearly.

You can add color descriptions to specific items in the prompt, and it should be rendered in color.

The crosshatch effect is strong even at lower weight (try 0.7 to 1.0), so you can tone it down for better prompt following or to reduce distortion.

I've also created a scribble drawing LoRA: https://civarchive.com/models/1179075/scribble-portrait-drawing-style