Original: However, his training in Wolgemut's studio, which made many carved and painted altarpieces and both designed and cut woodblocks for woodcut, evidently gave him great understanding of what the technique could be made to produce, and how to work with block cutters.
Simplified: But he had designed and cut woodblocks for woodcut as part of his training in Wolgemut's studio, and he had seen  many carved and painted altarpieces made in the studio.