The WFPC2 Filter Throughput directory contains throughput tables for all WFPC2 filters.
Instructions for downloading individual throughput tables can be found at the bottom of this page.
Post-mission scans of the filters, along with the inspection report, are available at: ftp://ftp.stsci.edu/instrument_news/WFPC2/filterscans/
How to calibrate WFPC2 Linear Ramp Filter data.
Prelaunch WFPC2 Optical Filters Specification (PDF 1.7 MB)