Is it permissible to take the full amount for printing a research paper without giving a percentage to the office, especially since the customer wishes to deal personally outside the office?

The contract between you and the office is a lease contract for completing a specific task (a shared employee). Since your dealings with them are "by the piece" and not as an employee, it is permissible for you to accept work from outside the office.

Regarding the client you came to know through the office: - If they came to you through the office, then the office is entitled to its agreed-upon share. - If they came to you directly without the office's mediation, then the entire payment is yours. - If no agreement was reached between the client and the office, and then the client came to you directly, the entire payment is yours.

However, it is not permissible for you to sabotage clients for the office, encouraging them to cease dealing with the office and deal directly with you, as this constitutes a breach of trust and harm to the office.