Literacy gives children an opportunity to benefit from others' knowledge and experience that far exceeds what they can achieve when reliant on learning orally via personal encounters. Little is known about young children's understanding and use of print as a source of knowledge. Three experiments investigated children's use and understanding of printed names as sources of information about the identity of unfamiliar targets. Children in Experiment 1 (N = 34, ages 5 years 5 months to 7 years 5 months) proactively used printed labels to correct their guesses. In Experiment 2 (N = 86, ages 3 years 7 months to 6 years 2 months), early readers offered a picture strip with labels (illegible to them) rather than one without labels to help a doll identify the target. Younger prereaders showed no such preference. In Experiment 3 (N = 69, ages 3 years 2 months to 6 years 2 months), early readers believed oral suggestions backed up with labels (illegible to them) over suggestions without such backing. Younger prereaders less frequently showed such trust in the reliability of information gained via print. Children may treat print as a reliable source of knowledge as soon as they can decode print for themselves, but not before. (Contains 2 tables and 1 footnote.)