The use of instrumentation and other techniques for monitoring and troubleshooting paper machine press sections has gained wide acceptance. The need to produce at lower cost has emphasized the need to better understand and optimize pressing efficiency. The information that follows has been compiled with an objective of providing information to the paper industry on available instrumentation and procedures for monitoring wet press performance. Information on the importance of techniques for measurement of several pressing parameters is included. Table 1 at the conclusion of this TIP includes specific information on equipment suppliers. The address of the suppliers can be found in the TAPPI Annual Directory, and other sources. The parameters discussed include: 1. Felt thickness 2. Sheet or felt total mass 3. Felt water content 4. Sheet water content 5. Degree of felt filling/openness (porosity/permeability) 6. Running felt length 7. Felt tension 8. Tradeline distortion 9. Felt and roll speeds 10. Press vibration 11. Press roll alignment 12. Press roll crown 13. Press roll temperature 14. Felt and sheet temperature 15. Felt dewatering flow rate 16. Felt fiber shedding. 17. Nip load and felt tension