| 1st. | The sensitizing solution contains too much iron chlorate. |
|---|---|
| 2d. | Exposure too short. |
The paper is stained.
The brush not kept clean while sensitizing.
Black spots.
They are generally due to metallic dust in the paste of the paper, or from particles of undissolved salt in the platinite solution.
NB: No good results can be expected unless the paper be kept absolutely dry before, during and after exposure, when using the former (original) process.
Impaired sensitiveness of the paper, want of vigor, tinged whites, muddiness, indicate dampness.