“It’s like painting with primary colors:

no subtle shades,” he said. “You’ve got to get their attention quicker, use exciting language. It’s a lot more demanding. I really have to be on my game.”

It may seem an odd venture for a songwriter of his stature, having toured the country to sold-out shows, and cowritten hits for bands like Sugarland. But he has a good reason — two, in fact.

“I have two little girls, and I wanted to write music that they could listen to while I was gone that was written for them. I feel like I’m fulfilling a parental responsibility,” Paul said. “Folk is music for the people, and I feel like I’m more of a folksinger writing these songs than I do singing my regular songs.”

Paul still places much of his focus on “grown-up” songwriting — which fans can hear Friday at The Blue Door — but the elements of children’s music are seeping in one way or another.

“I’m learning how to write more succinctly. Early on, the lyrics per square foot were pretty dense,” he said with a laugh. “Now there’s a lot more space.”

Listeners have made sure to reward his continued growth and maturity with more than just ticket sales and album purchases. When Paul parted ways with his old record label in 2008, he found financiers directly from his consumer base, to the tune of $100,000 in donations for recording and distribution.

“The outpouring … it was more than any record label had ever contributed to one of my projects before,” he said. “We were really amazed that much happened, right around the time the economy was crashing. Money was tight, so that was phenomenal.”

Such monumental support demanded a product worthy of it. Paul went into the studio to record last year’s “The Day Everything Changed” with a renewed — and clarified — sense of loyalty to his followers.

“It was like we all owned a part of it,” Paul said. “I knew I needed to do something they would all be proud of. Sometimes you are trying to please a record label, sometimes you are trying to please the critics, and this was a situation where I just wanted to put out the best record I could for the fans.”

Paul is now looking toward to getting back into the studio to record a follow-up for sometime early next year, still not resting on his laurels and wanting — now more than ever — to please his fans calling for new, good music.

“Each record sets the bar a little higher than the last,” he said. “I want to keep developing that way.”