Albrecht Altdorfer's pen and ink landscape drawings were all created in a horizontal format, where as he often preferred vertical for his paintings. It was most likely Huber who first started the technique of framing landscape drawings and selling them independently as you would a painting, something that we completely take for granted today. Nuremberg artist Albrecht Durer's drawings may also have been an influence on Altdorfer too, though more technical than through his choice of content for depiction. He preferred pen and white heightening in most cases when using this medium.
There is some belief that the artist and Wolf Huber may have met on the Danube in 1511 and there are many features in Altdorfer's drawings which points to a close relationship, or a clear mutual respect at the very least. It is important to remember that Renaissance art did not treat the skills of draughtsman as significant on its own, but more as a supporting tool to other mediums such as painting, sculpture and architecture. Huber had a different view and would number and date his drawings, something Altdorfer then took into his own career.
All that said, the influence would go both ways - the style of Huber's woodcuts took a direct influence from his colleague, plus also the great master, Albrecht Durer. Huber was to specialise in drawing as his career developed, with few paintings from his career surviving to the present day, and perhaps this specialisation contributed to Altdorfer’s great respect and interest in Wolf's work in this particular medium. Durer, by contrast, succeeded in countless different techniques across his productive and consistent career.
Wolf Huber was certainly less subtle a painter than Altdorfer, yet the latter lack quite the same guile and patience within his drawings. Perhaps this reflected the importance that both artists placed on these two opposing mediums. Huber would make smaller incisions into the drawing with single pen strokes, patiently building the scene without rush. He would also address blank regions of his drawings more thoughtfully than his Danube School colleague.
The idea of artists sketching outdoors was virtually unheard of during the Renaissance, with very artists prior to Albrecht Altdorfer taking this approach. Even some of Leonardo da Vinci's drawings which appeared to have been used this method effectively were later disproved as being heavily influenced by several generic Netherlandish landscape paintings. It is likely that plain-air drawing was undertaken earlier by Albrecht Durer, Titian and Fra Bartolommeo but very few others.