The state of Idaho has started using what officials believe are tamper-proof vehicle titles, safe from even the best of forgers.

The new titles were put into use last month. They're double the size of the old ones, printed in Idaho's centennial colors and have five tamper-proof features.Morris Detmar, titles operations manager with the Idaho Department of Transportation, said most states already have the safety features in use.

"We've had very minor security features in the previous ones," he said. "This one, we believe, is state of the art."

He said it's impossible to estimate how many state titles are forged each year, because word rarely gets back to the state. Forgeries usually are discovered in other states, and officials don't return the titles to Idaho.