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Factors that adversely affect the sensitive layer:

Sometimes some defects may appear in the negative photo despite observing all the necessary instructions during the photocopy or during the display operations. It can return the appearance of -
These defects are due to one of the following reasons:

First - Humidity: Gelatine absorbs evening steam. This absorption may be inconsistent, resulting in spots appearing on the negative after it has been shown. Some manufacturers of photographic materials enclose their products with moisture-resistant casings intended for hot regions. If these casings were opened, this was sufficient to cause some damage due to moisture. And an increase in caution, it is better to put some materials that absorb water vapor in places to store sensitive materials, such as calcium chloride or dried rice, if the storage is in a wide place.

Second - the length of the storage time: If the sensitive materials are stored for a long time after their manufacture, the silver salts granules become capable of being reduced in the apparent acid without being exposed to light. If imaging was done with it, we would get soft results, and the general color of the negative would be gray tone. It is possible to add some chemical compounds to the rendering solution to fix the defect. This is it
due to the length of storage.
Perhaps the best place to store for a suitable time is a dry, low-temperature place

Third - Chemical fumes: Sensitive layers are affected by fumes and gases, which helps to form the so-called chemical fog. Examples of these gases are:
Carbon gases resulting from the combustion of turpentine or oils. Fourth - the light fog This defect results from the arrival of chemical reactions. The fumes of some materials transmit any amount of light to sensitive materials, either directly or as a result of not wrapping them immediately after use. or as a result of being placed in intense light while encapsulated