So much of what makes it onto Canadian TV screens is triggered by the Canadian Television Fund - more than $927-million worth of homegrown production in 2005/06 - and producers and broadcasters have to stay on top of all the fine points to acquire crucial CTF cash.

It's a process that has changed significantly with the introduction of broadcaster envelopes in 2004/05.

In previous years, producers would submit their applications, then wait to see if their projects were selected to receive money from an oversubscribed fund. Today, most CTF cash is distributed through broadcaster envelopes, which represent the amount of CTF funds reserved annually for each caster. Producers still file the application, but only for projects preselected for CTF funding by a broadcaster. The application process itself has become more like seeking a final stamp of approval.

The broadcaster envelope system was initiated "to try to stop the situation of oversubscription and to create some predictability in the system," says Stéphane Cardin, CTF's VP of strategic policy planning and stakeholder relations.

While aboriginal and French-language productions outside Quebec, as well as versioning assistance and some development financing fall under the CTF's Special Initiatives Stream, the majority of applicants for production funds go through the broadcaster envelope stream. This year, an individual envelope was created for English drama, increasing the stream's impact on homegrown production.

Determining how the CTF calculates the amount in each broadcaster's envelope has been an evolutionary process open to annual review. There are currently four objective criteria of varying weight.

One factor is a broadcaster's historic access to the CTF. This consideration is intended to create a measure of funding stability for casters from year to year, and was the sole criterion used to determine the first envelopes in 2004/05. (For 2007/08, this will count for 30% of English envelopes, and 45% for French.)

A second measure is the amount of regional production a broadcaster licenses (20% for English, 10% for French), while a third looks at the extent to which a broadcaster's licence fees exceed the average, meaning that higher cash commitments from broadcasters help to increase their envelopes (10% for English, 15% for French).

"If a broadcaster demonstrates a significant amount of support for Canadian production, we think that's a good thing. Reliance on the fund is not entirely a good thing," says Kathy Corcoran, director of research and data at the CTF.

The final and most significant criterion, according to Cardin, is audience success (40% for English, 30% for French). While this factor generally applies to ratings for CTF-financed shows, the fund will consider the audience success of shows financed without CTF money, if such shows still meet CTF guidelines.

In addition to calculating broadcaster envelopes, the CTF designs general and genre-specific criteria that all projects must meet for funding eligibility.