Bryan Cranston keeps broadening his acting range in Trumbo

When Bryan Cranston was filming Trumbo – the new drama about the screenwriter Dalton Trumbo, who was blacklisted in the 1950s for being a member of the Communist Party – he made his director, Jay Roach (Game Change), promise him something. Trumbo was a colourful guy, always adorned with eyeglasses and mustaches, a cigarette holder jammed between his teeth, a cocktail in his hand, and, as if all that weren't enough, a parrot on his shoulder (a gift from Kirk Douglas, for whom he wrote Spartacus).

Cranston, 59, is a capital-A Actor; he loves props. But he knew that an embarrassment of riches, when used improperly, can become simply an embarrassment.

So he told Roach that, in order to find the sweet spot in every scene, he'd have to lay on too thick whatever irascibility or lovability or eccentricity he was playing. He'd rely on Roach to tell him when he'd gone too far, then he'd reel it back in.

"I like to go out on a limb until I hear it start to crack," Cranston says. We're in a hotel room during September's Toronto International Film Festival, and he's a thoroughly entertaining one-man show, gesticulating, clutching his heart, dropping into Trumbo's rumbling elocutions with glee. He enunciates. He speaks in italics. "Some actors are content if their spectrum goes from here to here," he continues, holding his hands out two feet apart. "That's fine – but don't they ever wonder how far it could go?"

Cranston has gone all the way – his professional and personal arcs are wide. After 20 years of relative obscurity as a working actor (a stint on the soap opera Loving; a recurring role as Jerry's dentist, Tim Whatley, on Seinfeld; a small role in Saving Private Ryan), he hit the jackpot in 2000: a lead role on a hit sitcom, Malcolm in the Middle.

When that show wrapped six years later, he was offered other sitcoms. Instead, he "turned sharp left" to play the majestically complicated Walter White on Breaking Bad, earning four best actor Emmys and a primo spot in TV's current golden age. When that show ended, Cranston refused other badass roles and headed to Broadway, where he won a Tony for playing Lyndon B. Johnson in All the Way. (He and Roach recently filmed an adaptation for HBO, with Steven Spielberg producing.)

"It's all about Bryan's range," Roach says in a separate interview. "Trumbo's existence ranged from the lowest of lows to this truly noble, loving man who cared about his country. He experienced depths – cavity searches in jail – and highs, winning two Academy Awards. Bryan has that range. Also, Trumbo loved performing; his passions, gestures and orations were larger than life, which is a joy for Bryan to do. I sensed all that was in him, and oh man, it really is."

Cranston knew about lows. His parents were actors with uneven success. "Things were up and down, down and down, up, down," he says. "We put a pool in one year, the next we didn't have money for the chemicals. Our house was foreclosed. There was alcoholism. My mother and father had been den mothers and coaches on ball teams, and everything was great, until it wasn't." When Cranston was 11 years old, his father left. They didn't speak for the next 11 years, until Cranston sought him out and they reconciled.

"At 11, I realized, 'Nothing is real,'" he says. "That introverted me for a long time. Made me untrusting, hesitant." Acting helped him find his footing. "But I was never the guy in the shower going, 'I want to thank the Academy.' I know how things can go away."

So now to be beyond financially secure, with a Ventura beach house he designed, a wife of 26 years (the actress Robin Dearden) and a daughter at the University of Southern California (she was an extra in one of the Breaking Bad episodes he directed) – "I'm having a blast," Cranston says. "My wife and I look at each other and just smile."

He might want to rethink his "no shower speeches" policy. The gusto with which he threw himself into Trumbo shows. Trumbo wrote in the bathtub, so Cranston had to spend long days "just soaking there, turning into a prune," Roach says. Trumbo also talked aloud as he wrote, acting out every character; Cranston improvised those scenes, muttering wild scenarios during long closeups. "Some day I should cut together the stories that Bryan came up with," Roach says, laughing.

Cranston is also beloved by colleagues, including the cockatoo that plays Trumbo's parrot. "That bird was obsessed with Bryan," Roach says. "It would climb into his hair, it would eat his mustache. There was a lot of footage we couldn't use because the bird was so into Bryan."

Cranston believes in Trumbo's message: "It's a reminder of the NSA and wiretapping and the dangers of governmental overreach," he says. "More importantly, its message is: 'You may be vehemently opposed to someone's opinion, but you need to fight for their right to voice it.'"

But mostly he signed on to hear those limbs crack. "I don't want to be too comfortable," he says. "I want to keep moving, keep hunting for more." He discovered a key into LBJ, for example, on his second visit to the Johnson Library in Austin, Tex. He missed it the first time; it was tucked into a corner. It was a letter from Jacqueline Kennedy, thanking Johnson for writing to her two children about their father.

"I looked at the date and went: 'Wait a minute,'" Cranston remembers. "This is four days after Kennedy's assassination. In that moment of tragedy and shock, with everything else he had to do, he took the time to write two letters to two little children." He sucks in a breath. "That spoke to me about the core of that man. And that helped – mmm – propel me.

"As an actor, you never really know what you're looking for," Cranston sums up. "You have to be open to anything. You have to be a funnel. You have to be insatiable."