How to enlarge a picture using a grid

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A common art project for students in art classes or people who just enjoy drawing or painting is to enlarge a picture using a grid. This grid method allows a small reference picture to be transferred to a larger paper or canvas as the beginning sketch of an art project.

Enlarging a picture using a grid requires careful attention to detail, but the final product is usually a surprising likeness of the original picture.

Choose the size of the enlargement, ensuring that it is proportional to the original picture. For example, if enlarging a 4- by 6-inch photograph, the enlargement should also have a ratio of four to six, whether it is 8 by 12 inches, 10 by 15 or 16 by 24.

Draw grid lines in pencil on both the original small picture and on the paper or canvas on which it will be enlarged. They should be divided into grids with the same number of squares in the same orientation. There should be at least 20 squares to ensure enough information to transfer the picture well. For example, when enlarging a 4- by 6-inch photo to a 16 by 24-inch canvas, the grid lines could be drawn every inch on the photo to divide it into 24 squares, and then every 4 inches on the canvas to also divide it into 24 squares.

Label the grid squares with letters going across and numbers going down. This helps to make sure that elements of the reference picture are going in the right squares during the enlargement.

Sketch the picture onto the canvas, one square at a time. This sketch should focus on the overall shapes and lines, paying careful attention to the placement of lines and shapes as they move from one square of the grid to another. If one line or curve stretches across much of the picture, as in a photograph of a face, it may help to mark the points in all the boxes where that line passes, and then connect those points in a fluid curve, paying attention to its shape on the reference picture.

Erase the grid lines from the final picture that is being drawn, being careful to not erase the sketch as well. If the final picture is going to be a painting, the grid lines can be left if they are going to be painted over by something dark enough to cover them.

Fill in details in all parts of the drawing or painting to finish enlarging the picture. Continue looking at the reference picture for help with what the details should look like.