The simple answer is "no"... you don't need to be a fine artist to be a graphic designer. While it could help your career and your creative side, it is not necessary to be a sketch artist, painter or other type of artist in the traditional sense. Graphic design is about taking elements such as type, photos, illustrations, and color and combining them to create effective messages. In many cases, an artist will be hired to create a painting, illustration or drawing for a project that will then be handed off to a graphic designer to incorporate into the piece, whether it be an album cover, poster, business card, book cover or other graphic work.
In some cases, a graphic designer may also create his or her own illustrations, drawings and paintings, but it is not considered an essential part of a designer’s skill set. It can be beneficial to a career or business if you do create your own artwork, as you could save money by completing more tasks yourself and any additional creative skills can improve your chances at landing certain design positions.
It is important to understand that you should have an understanding of the artwork that may be incorporated into your work, as well as the creativity to bring it together with other elements effectively. Even if you are not creating the drawing or painting, you will want to understand the use of color, shapes, lines and the other elements of graphic design.