|Use of Whitener also does not affect the Addmen optical mark recognition software. But it depends on the MCQ examination policy what the examination body allows.|
Most examination bodies discourage the use of whitener on OMR sheets. Technically, there is nothing to worry about using whitener to erase a wrong bubble filling to make the right one. The OMR software is designed to read dark marks. So, when the whitener is applied to a bubble, no dark mark is left at that place. There is no confusion in this situation. Still, the practice of using whitener on OMR sheets is not common. Here are the reasons:
The whitener is usually thick coated and may start chipping while bending, stacking and storing the sheets during the scanning process.
These chipped inks of the whitener may fall on the scanner lens and create shadow marks on the image of the sheet. This can cause confusion for the OMR software, thus hampering the reading process.
Another problem is that if the whitener is not dried properly before submission, it can stick to the adjacent sheets, damaging the other sheets. It can also create impression on the adjacent papers, which can be problematic, especially in case of duplex OMR sheets.
A legal issue may also arise due to the use of whitener on OMR sheets. As there is no proof of who actually applied the whitener on the OMR bubble, the student may contest that it was done by the examiner or evaluator.
These are the reasons for not allowing the use of whitener on OMR sheets.