How to rule a straight line or ellipse in a painting app
Use the ruler or the ellipse guide in Easel by Zaweba. Strokes that start on a guide follow it, so lines and ellipses come out clean every time.
Rule a straight line in Easel by Zaweba with the ruler, and draw an ellipse with the ellipse guide. Strokes that start on the ellipse guide follow it, so your brush, pencil or pen gives a clean curve while the mark itself still looks hand made. The same set of drawing aids includes a French curve, a compass, proportional dividers and a grid.
That combination is what makes these guides useful in a natural-media painter. A ruled line in Easel is still a pencil line, with the grain of the paper showing through, or a brushstroke with real paint in it. It is just in the right place.
Why painters use guides at all
Straight lines and ellipses are among the hardest things to draw freehand. A wobbly horizon makes a seascape feel off. A lopsided ellipse at the top of a cup or the base of a vase makes the whole object look as though it's tipping. Architectural painters, still life painters and sign writers have always used rulers, templates and curves for exactly this reason.
In a real studio you lay a ruler on the paper and run your pencil along it. Easel works the same way, which is why the habit carries over.
Ruling a straight line
Pick the ruler from the guides. Place it where you want the line, then start your stroke on it and draw along it. Use a pencil or a fine pen for construction lines, or a brush for a painted edge such as a horizon, a windowsill or the edge of a table.
For long architectural lines, draw them lightly first in a hard pencil and paint over them later. Light construction lines disappear under paint, while a hard, dark ruled line can look mechanical.
Drawing an ellipse
Choose the ellipse guide and place it where the curve should go. Then start a stroke on the guide, and the stroke follows it. This is ideal for the rim of a cup, a plate seen at an angle, the top and bottom of a jar, wheels, and round windows or arches seen in perspective.
A tip from still life painting: the ellipse at the top of an object seen from above is usually narrower than the one at its base, because you're looking down at it more steeply. Draw both before you paint and the object will sit properly on the table.
The other drawing aids
The French curve gives you smooth, flowing curves that aren't part of a circle, for boat hulls, vase profiles and lettering. The compass draws circles. Proportional dividers help you measure one distance and compare it with another, the classic way to check that a figure's head and body are in proportion. The grid is for the old squaring-up method, matching the squares of a reference to the squares of your canvas.
Guides live on the tracing-paper or acetate sheet that sits over the painting, and Ctrl+H shows or hides the sheet. Hiding it lets you see your painting without the clutter of guides.
Getting clean lines that still look painted
Let the material do its work. A ruled pencil line on rough paper will catch the grain, and a ruled brushstroke will carry and lose paint as a real brush does. That variation is what stops the line looking like a vector drawing, so don't fight it.
Rule the structure and paint the rest freehand. Use guides for the horizon, the buildings and the ellipses of objects, then paint foliage, clouds, people and surface detail by hand.
Check with the mirror view. Flipping the picture shows whether a ruled vertical is really vertical, and the view never affects the painting.
Steadying your hand without a guide
Not every careful line needs a ruler. For small detail, Easel's mahl stick steadies your hand, just as the long padded rod does in a real studio. Many painters use both: guides for geometry, the mahl stick for lettering and fine touches.
Between them, the guides in Easel by Zaweba take the anxiety out of straight lines and ellipses, so you can save your attention for the painting itself.
