Non Judicial Stamp paper and Legal Paper (Plain Paper) both are the different terms in aspect of their nature.
On Non Judicial Stamp Paper Magistrate never write the decision of the Case, though Magistrate write the decision on the Legal Paper (Plain Paper).
That is why it is called as Non-Judicial Stamp Paper.The Paper which not be considered as Judicial.
Why Non Judicial Stamp Paper is required and What is the differences between 10 Rs, 20 Rs, and 50 Rs non-judicial stamp paper ?
The Government collects the revenue through the sale of Non-judicial stamp paper.
For each Article there is a Separate stamp duty like –
Stamp Paper of Rs. 10 used for Affidavit, Declaration, Undertaking etc.
Stamp Paper of Rs. 20 for Special Power of Attorney.
Stamp Paper of Rs. 50 for General Power of Attorney/Agreement.
Stamp Paper of Rs. 100 for Indemnity Bond, Guarantee Bond. Customarily, a stamp paper of Rs 20 – Rs 100 can be utilized for a rent agreement of an 11-month duration. You can use it any time. But if you want to cancel such a stamp paper, you have to surrender the same to Collector, for refund of amount within a period of six months from the date of purchase. 5 lakhs for selling the house. It was written in the agreement that the buyer should settle the remaining amount (i.e.60 lakhs) within 3 months from the date of giving advance money (16.06. 2008). … The agreement of sale on Rs 20/- stamp paper is invalid.
Reference: Civil Procedure Code, 1908