Transferring with a Grid
The grid method involves two grids — one drawn over the original image and another drawn on the painting surface. The objective is generally to resize an image so it fits into your composition. The grid is a way of breaking a picture down into smaller, more manageable sections. The grid provides a set of reference lines that can be as simple or complex as you need. It is a tool to serve your needs, to accomplish your purpose. You may want to make a larger copy of an entire photograph. You may want to enlarge one object on a magazine page. You may want to create a larger version of a drawing in your sketch book as the basis for a painting. You may have almost completed a drawing but need help with the details of a person's eye. In each case, the grid method can help.
The first step is to draw a grid of equal squares over a reference drawing or photo. This can be done by drawing a grid directly on the original, drawing a grid on a photocopy or by drawing the grid on a sheet of acetate and placing the acetate over the image. The squares of the grid can be any size, from ¼ to one inch. The size you choose will depend on your needs.
The second step is to draw another grid on your painting surface. The size of the grid on the painting surface will depend on your objective. If you want the image on the watercolor paper to be the same size as the original, draw the second grid the same size as the first. If you want to enlarge the image, draw the second grid with larger squares. If you want to reduce the image, draw a smaller grid on the watercolor paper.
The third step is to transfer the image from the original to the painting surface, drawing one segment at a time. The key to this method is to focus on drawing lines, angles and proportions in relation to the grid lines. Rather than drawing things with names (the iris in Mary's eye), you are drawing a line that starts half-way up the grid line on the left, arches upward until it just crosses the top grid line, and then descends to the upper right-hand corner point. Repeat this process for each square of the image.
Make any additions or corrections to the drawing as needed. Erase the grid lines on the painting surface.
Create a Grid Directly on the Original Image
Option 1. Draw a grid of equal squares directly on the original or on a photocopy of the original. The easiest grid to make is one that divides the original in half vertically and in half horizontally. This divides the original into fourths.
Option 2. Scan the image and open it in an image editing program like Photoshop Elements. In Photoshop Elements, select View > Grid. Save the image with the grid. Print the gridded image. To change the size of the grid sections, select Preferences > Guides, Grid & Slices, then set the size of the grid.
Create a Acetate Grid to Place over Original Image
Option 1. Using a ruler and a fine tip felt pen, draw a grid on a 8½ x 11" acetate sheet like an overhead transparency film. Make the sections of the grid 1 x 1" or ¼ x ¼" depending on the detail you want. Make the lines as fine as possible. You can use the entire grid, or you can cut the large sheet into smaller pieces.
Option 2. In a graphics program like Adobe Photoshop Elements or Adobe Illustrator, create a grid. Print the grid onto overhead transparency film that is designed to go through a printer.
Place Acetate Grid Over Original Image
Tape the original image to a piece of paper, then tape the transparent grid on top of the image. This will keep the reference lines from moving.
Create a Second Grid on your Painting Surface that is Proportional to the First
First, create a rectangle that is proportional to the first image. Then, create a grid with sections that are proportional to the first grid.
To double the size of the 5 x 7 original, create a new rectangle that is 10 x 14 inches. If the grid on the original is ¼ inch squares, the new grid will be ½ inch squares (2 times ¼).
If the original image was divided into fourths, divide the proportional rectangle into fourths.
Draw lightly if the grid lines are going to be erased later.
TIP: To make measurements easier, use 1 cm squares on the original grid. Then the size of the proportional grid sections with be length of one side of the larger rectangle divided by the corresponding side of the smaller rectangle. For example, if the original is 4 x 6 and the longest side of the larger rectangle is 11, the size of the larger grid will be 11/6 or 1.83 cm. (1.83 cm will be easier to find on a ruler than 1.83 inches.)
Create a Proportional Grid on Tracing Paper
Rather than drawing a grid on watercolor paper and then having to erase it, draw the grid on a piece of tracing paper. Use this grid to draw the resized image onto the tracing paper. Make any corrections that are necessary before transfering the image to the painting surface.
When the drawing is complete on the tracing paper grid, place a sheet of transfer paper on top of the painting surface. Then tape the tracing paper drawing on top of the transfer paper. Use a stylus, ball point pen, or pencil to trace the lines of the drawing.
Create a Proportional Rectangle that is not a Simple Multiple of the Original (2X, 3X, or 4X etc.)
On the watercolor paper, draw the base of the larger, proportional rectangle the length you want the enlarged image to be.
At each end of the base line, draw a vertical line. Make these vertical lines longer than you expect the height of the new rectangle to be.
Place the lower-left corner of the original at the lower-left of the new rectangle. Draw a diagonal that extends from the lower-left corner, through the upper-right corner of the original, and across the vertical line on the right.
From the point where the diagonal crosses the vertical line, draw a horizontal line until it crosses the other vertical line.
Now you are ready to begin constructing the grid in the new proportional rectangle.
Create Diagonal Grids
The advantage of a diagonal grid is that there is no need to make any measurements.
This is a two-step process:
- draw diagonals
- draw vertical and horizontal lines where the diagonals cross
Repeat the process of drawing diagonals, verticals and horizontals until you have enough reference lines to accomplish your purpose.
Follow this process twice — once on the original and a second time on the larger proportional rectangle.
Draw two diagonal lines: one from the upper-left corner to the lower-right corner, another from the upper-right corner to the lower-left corner.
At the point where the two diagonal lines cross, draw a vertical line and then draw a horizontal line.
Add diagonal lines in each of the four quadrants.
Where the diagonals cross, add vertical and horizontal lines.
In a more detailed area, add another diagonal line.
Where the diagonals cross, add vertical and horizontal lines.
Enlarging Sketches from a Sketch Book
Enlarging drawings from you sketch book is easier if you start with sketches that are proportional to you favorite painting format.
Let's assume you paint most frequently on a quarter sheet of watercolor paper that is 11 x 15". Let's assume further you use the standard 16 x 20" mat that has a window of 10.5 x 13.5".
Create a sketch book template from card stock that is 2 x 2.5". This will be proportional to the mat opening rather than proportional to the dimensions of the paper. Include tic marks around the edges of the template that will divide each edge into fourths.
Draw around the sketch book template. Draw the tic marks around the rectangle. Make the sketch. When satisfied with the drawing, use the tic marks to draw a grid over the sketch.
Add additional reference points to the gridded sketch: where the drawing crosses the edge of the format, where an object in the sketch begins and/or ends, where lines of the sketch intersect the grid lines.
Consider using a set of proportional templates rather than just one. Use a small template for quick value sketches — credit card size or smaller. Use a larger template for detailed sketches to be gridded — 4 x 6" or 3 x 5". Finally, use a large template for watercolor paper. This large template should be the size of the opening of the mat for that size paper. You might want to make the template slightly larger so line will not show inside mat opening.
Templates could be kept in an envelope glued to the inside cover of the sketch book.