• The Physics: Technical pens use pigment-based ink, but not all of them are waterproof immediately.

• The Rule: If you plan to paint over your lines with watercolor or marker, you must buy pens explicitly labeled "Archival" or "Waterproof."

• The Wait: Even waterproof ink needs ~5 minutes to cure. If you paint over it instantly, it will smear.

These are the standard for 90% of artists. They have a plastic or felt nib encased in metal. When they run out, you throw them away.

1. Sakura Pigma Micron

• The Ink: Sakura invented "Pigma" ink. It is the definition of archival- chemically stable, waterproof, and fade-resistant.

• The Feel: The nib is slightly soft (felt-like). If you press too hard, you will mash the tip and ruin the line width.

• The Flaw: The nibs are fragile. The "005" size (microscopic) often breaks or bends before the ink runs out.

2. Uni Pin

• The Difference: The nib on a Uni Pin feels harder and more plastic than a Micron.

• Why use it: It is more durable. If you have a "heavy hand" (you press down hard), Uni Pins last longer than Microns. The black ink is also slightly cooler/bluer than the warm/brownish black of Sakura.

3. Staedtler Pigment Liner

• The Feature: They have "Cap-Off" technology. You can leave the cap off for 12 hours, and it won't dry out. (Do this with a Micron, and it's dead in 30 minutes).

• Verdict: The best choice for forgetful artists or chaotic sketchers.

Rotring Isograph & Rapidograph

• The Mechanics: A gravity-fed needle creates the line.

• The Feel: Scratchy. You are dragging metal across paper. It gives extreme feedback.

• The Line: Perfectly consistent. A 0.5mm Rotring makes a 0.5mm line forever, whereas a felt tip Micron gets fatter as it wears down.

• The Ink: You fill a reservoir with high-density India Ink (Isograph) or use cartridges (Rapidograph). It is the blackest ink on earth.

The Maintenance Headache

• The Trap: If you let the ink dry inside a Rotring, the pen is destroyed. The hair-thin wire inside fuses to the tube.

• The Commitment: You must clean these pens with water and fluid regularly. They are high-maintenance tools for serious architects and illustrators only.

Rotring ArtPen / Lamy Joy

• What they are: Fountain pens with a specialized "sketching" nib.

• Use: They offer line variation (thick to thin) depending on pressure or angle, unlike technical pens which are "monoline" (same width always).

• Note: Most fountain pen ink is NOT waterproof. You must buy "Platinum Carbon Black" ink if you want to paint over it.

Technical pens are numbered by millimeter width.

• 005 (0.20mm): Hairline detail. Textures. These are fragile).

• 01 / 02 (0.25mm): General hatching and fine lines.

• 03 / 05 (0.35mm - 0.50mm): The "Standard" outlines. If you only buy one, buy an 05.

• 08 / 1.0 (1.0mm): Thick borders and filling in black areas.

The Best All-Rounder:

Try the Uni Pin Fine Line Set.

• Why: They are tougher than Microns, waterproof, and the "dark grey" body looks professional. They rarely break under pressure.

The "Standard" Pick:

Sakura Pigma Micron.

• Why: They are available in every store on earth. If you run out of ink mid-project, you can find a replacement easily.

The "Pro" Upgrade:

Rotring Isograph.

• Why: Buy one of these (size 0.35) only if you are obsessed with perfectly black, crisp lines and are willing to clean it. It feels like a surgical instrument compared to the plastic disposables