Answer:
The weights of paper used for coated abrasive backings are designated by the letters A, C, D and E
Step-by-step explanation:
The letter designation of the weights of paper backings for different applications are;
'A' Weight - Paper meant for use in finishes in abrasive projects. The paper is light (weight) touch grade of abrasive paper
'C' Weight - The 'C' designated paper is the medium light grade which offers more strength and bendability and it is suitable for woodwork by a cabinet maker
'D' Weight - The 'D' weight category is a medium heavy paper
'E' Weight - The 'E' weight category is a strong paper category, used for discs, coarse sheets, and belts
Therefore, the letters A, C, D and E are used to designate the weights of paper used for coated abrasive backings.