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Single-Line Contour Drawing of a Cylindrical Battery
Learn to draw a battery in pure contour line, capturing terminal and casing edges without shading or cross-contour volume lines.
Free lesson
Four exercises
Worked answers
Object Drawing Lessons
This contour drawing lesson is side-view only. It records the visible outer boundary of a cylindrical battery with one continuous line, including its raised top terminal, casing seam, and base rim, while omitting shading and internal volume marks. You will use an explicitly defined convention for line placement and a checklist to verify edges. All measurements are hypothetical examples; measure your own equipment before drawing. The printable reference, worked example, and blank frame are planned resources, not yet built.
Practice materials: Printable downloads are not available for this lesson yet. Use the instructions and four exercises below.
Defining the contour convention
A contour line marks the outer silhouette of the battery as seen from one viewpoint. For a side view, draw one continuous closed line that starts at one base rim, travels up that casing side, over the flat top and terminal bump, down the opposite casing side, and across the base back to the start. Do not lift the pencil to add shading or cross-contour volume lines; those are excluded. Where the terminal meets the flat top, the line changes direction sharply. Where the casing edge meets the cap, the line may show a small step or ridge. Use a single line weight throughout; keep the line unbroken from start to finish.
Keep the drawing contour-only: do not add label lettering, shading, or cross-contour volume lines. The task is the single visible outer silhouette of the battery casing and terminal, so internal text is outside the exercise.
- Stand the battery upright on its base with the terminal at the top, and observe its side profile at eye level.
- Mark the start point at one base rim.
- Draw one continuous closed line from one base rim, up that casing side, over the flat top and terminal bump, down the opposite casing side, and across the base back to the start.
- At the casing edge where the cap meets the cylinder, show the step or ridge with a short change in line direction.
- Return to the start point without lifting the pencil; do not add shading or internal volume lines.
Terminal and casing edge details
The terminal is a small raised button. From above, its rim is a closed loop inside the battery’s top surface; that top view is outside this side-view lesson and would not be part of the single outer silhouette. From the side, the terminal appears as a bump on the top edge. Draw the bump as part of the single line: the line rises over the terminal, then drops to the flat top. The casing edge is the seam where the metal cap meets the cylindrical body. This seam often shows as a thin ridge; represent it with a short inward or outward step in the contour line, not with a separate line. Keep the step small relative to the battery height. For example, if a battery is 50 mm tall, a 1 mm step is a hypothetical example of a subtle ridge; measure your actual battery to choose a proportional step.
- Identify the terminal's highest point and the flat top on either side.
- Draw the line up and over the terminal, then down to the flat top.
- Locate the casing edge seam; note whether it steps inward or outward.
- At the seam, change the line direction by a small step, then continue down the casing.
- Check that the terminal bump and seam step are both present in the single line.
Edge checklist and self-check
After drawing, use this checklist: (1) one continuous line from start to end; (2) terminal bump visible; (3) casing edge step visible; (4) base rim included; (5) no shading or cross-contour volume lines; (6) line weight consistent. If any item is missing, redraw only that part without lifting the pencil if possible. The checklist is part of the planned printable, but you can write it on a separate sheet now. Measure your battery's height and terminal width with a ruler; record these as hypothetical examples only if you are not measuring a real object.
- Trace your drawn line with a finger to confirm it is continuous.
- Point to the terminal bump and the casing edge step.
- Confirm no shading marks exist.
- Compare line weight along the whole contour.
- Note one improvement for the next attempt.
Worked example
Draw a side-view contour of a battery 50 mm tall with a 5 mm terminal bump and a 1 mm inward seam step. Use one continuous line.
Worked answer
Start at the left base rim. Draw up the left casing side to the seam. At the seam on the left side, make a small inward step of 1 mm (hypothetical example), then continue up to the flat top. Rise 5 mm over the terminal bump, drop to the flat top on the right, then draw down the right casing side to the right base rim. Draw across the base back to the start. No shading or internal volume lines.
Four practice exercises
Exercise 1
Draw a side-view contour of a battery 40 mm tall with a 4 mm terminal bump and a 0.8 mm outward seam step on the left side. Describe your line path.
Show answer and check
Start at the left base rim, go up the left side, make a small outward step of 0.8 mm (hypothetical) at the seam, continue to the flat top, rise 4 mm over the terminal, drop to the flat top on the right, go down the right side to the right base rim, then draw across the base back to the start point, closing the loop.
Why: The single continuous closed line must include the terminal bump and the seam step without lifting; the prompt specifies an outward step on the left side, so the answer follows that direction and returns to the start point.
Check: Trace the line for continuity; confirm bump and step are present; confirm no shading.
Exercise 2
Draw a side-view contour of an upright cylindrical battery 50 mm tall with a 5 mm raised terminal and a 1 mm inward casing-seam step. A practice sheet also shows a small closed circle inside the casing side. Draw the outer contour, then identify whether that circle belongs to the contour.
Show answer and check
Draw one closed side silhouette that includes the raised terminal and the seam step. The small circle inside the casing is an internal surface mark, so it does not belong to the outer contour and should be left out of the contour-only drawing.
Why: A contour traces the boundary between the battery and the surrounding space from the chosen side view. An enclosed mark inside the casing does not change that outer boundary.
Check: Trace the outside path once from the base rim, over the terminal profile, down the opposite casing side, and back across the base. Confirm the seam step is included and no interior circle is joined to the closed outline.
Exercise 3
Draw a side-view contour of a battery with a 6 mm-high raised terminal and one casing-edge step. Explain how both fit the single outer contour.
Show answer and check
Draw one closed outer contour: rise along the casing side, make the small casing-edge step, continue to the top, rise 6 mm over the terminal bump and return to the top, then descend the opposite side and close the base. The raised terminal is part of the side-view silhouette, not a separate inner circle. Do not add shading.
Why: In side view, a raised terminal changes the battery’s top outline, so the bump can be integrated into one continuous silhouette. From above, a centered terminal lies inside the casing outline and would need a separate inner mark; this exercise uses the side view to keep the one-contour convention coherent.
Check: Trace the outer contour as one closed loop; confirm the terminal bump joins both sides of the top edge and the casing step is part of the profile. Do not draw a separate terminal loop or add shading.
Exercise 4
Measure a real battery: record height, terminal width, and seam step. Draw the contour and label your numbers as hypothetical examples if not measured.
Show answer and check
Example: height 50 mm, terminal 5 mm, seam step 1 mm (hypothetical). Draw single line with bump and step; label numbers as hypothetical if not from measurement.
Why: Measurement grounds proportions; labeling avoids claiming invented standards.
Check: Compare drawn proportions to recorded numbers; verify checklist items.
Common mistakes
- Lifting the pencil to draw the terminal as a separate circle. Integrate the terminal into the single line by rising over it and returning to the flat top.
- Adding cross-contour volume lines on the cylinder. Remove them; contour-only means no internal volume marks. Keep only the silhouette and seam step.
- Making the casing edge step too large. Measure the actual seam ridge and scale the step proportionally; a 1 mm step on a 50 mm battery is a hypothetical example.
- Adding label lettering or internal marks to a contour-only battery drawing. Omit the label and keep the single outer silhouette; shading and cross-contour marks are outside this task.
Self-check rubric
- One continuous contour line from start to end.
- Terminal bump clearly integrated into the line.
- Casing edge seam shown as a small step.
- Base rim included and closed.
- No shading or cross-contour volume lines.
- Line weight consistent throughout.
- Drawing contains the requested outer contour without irrelevant lettering, shading, or cross-contour marks.
Questions and answers
Can I use a ruler to measure the battery?
Yes. Measure height, terminal width, and seam step. Label any chosen numbers as hypothetical examples if you are not measuring a real object.
What counts as a casing edge?
The visible seam or ridge where the cap meets the cylindrical body. Show it as a small step in the contour line.
May I draw the battery from above?
No. This lesson is side-view only. A top view shows the terminal rim as an internal closed loop, separate from the casing’s outer silhouette, so it does not meet the single-contour task here.
How do I check my drawing without the planned printable?
Use the six-item edge checklist in the third section and trace your line to confirm continuity.