Tempted by the low price I have some 10-year-old Kodabrome photographic paper to try as paper negative in my large format 10×8 1900s field camera.
Initial results show that is “fast” as its technical description says – at least ISO12 as compared to 6 for ilford multigrade RC paper. (nb ISO values vary with the type of light and, outdoors, with the amount of UV light – which varies by cloudiness, pollution and season! On a bright summer day the effective ISO can be 25)
The initial images show a much softer tonal gradation compared to the ilford paper and no pre-flashing is needed. Whether this is because if the age of the paper or its chemistry I don’t know – but I love it!