# Paint underwater koi in Aquarell: separate body, markings and surface

Language: en
Canonical: [Paint underwater koi in Aquarell: separate body, markings and surface](<https://allluckly.cn/en/guides/aquarell-koi-underwater/>)
中文：[中文 HTML](<https://allluckly.cn/guides/aquarell-koi-underwater/>)
English: [English HTML](<https://allluckly.cn/en/guides/aquarell-koi-underwater/>)
Published: 2026-10-26T00:00:00+08:00
Modified: 2026-10-26T11:37:28+08:00
Author: Bison

Paint a turning koi with a curved body, delicate fins and restrained surface cues that place it underwater.

English translation of the [Chinese original](<https://allluckly.cn/guides/aquarell-koi-underwater/>), translated on 2026-10-26. Original publication dates, attribution, code and version notes are retained.

An underwater koi is more than a fish-shaped sticker with ripples. Paint one from above, curving its body, wrapping markings around its volume and adding restrained surface reflections. Finish one coherent fish before surrounding it with decorative pond elements.

## Set up a separate study

Use an approximately 1400×1600 px portrait canvas, leaving swimming space before the head and clear water around the tail. Separate water colour, body, red patches and surface reflections. Test broad water strokes and fine fin lines, keeping the body governed by its axis rather than surrounding ripples.

Before colour, check head width, tail stalk and the inner bend. Save an axis-and-silhouette version before markings. Keep the fish and surface independently hideable so later you can distinguish weak body structure from reflections that fragment an otherwise coherent contour.

## Connect the head and tail with an axis

Draw a gentle swimming curve. Make the head broad, the front body fullest and the tail stalk progressively narrower. Tighten the inner bend and open the outer curve. Establish head, trunk and stalk as three connected masses before joining them into a continuous silhouette.

Keep the snout blunt and place the eyes forward on either side. Paint a warm pale body with a lighter back and grey-blue sides before adding scales. If it resembles a rubber tube, broaden the head and front body and narrow the tail stalk instead of adding more markings.

## Spread the fins with the movement

Open the tail from the narrow stalk into a softly forked fan, with one side wider during the turn. Place smaller pectoral fins behind the head. Start with pale shapes, then add a few radiating lines. Avoid turning all fin edges into dark rigid plastic outlines.

Let the water colour show through the fins, with a darker root and fading outer edges and lines. Uniform faintness can make a fin look detached; uniform outlines make it rigid. Establish the root-to-tip transition before changing the opacity of the entire layer.

## Wrap the red markings around the body

Place three unequal red patches behind the head, near mid-body and before the tail, leaving white gaps. Keep their overall flow along the body. Narrow patches as they turn onto the sides and omit occluded areas rather than placing complete flat symbols on the back.

Shade the red patches with the same lighting as the white body: lighter on the back and darker on the sides. Hide them briefly to check the body shading, then restore them. They should feel attached to the surface rather than interrupt its volume with flat colour.

## Use a few surface cues across the fish

Use broad muted blue-green water variations. Add two or three incomplete pale ripple arcs around the fish, then let one cross it softly. Keep the crossing faint and broken rather than an opaque white cord. With few cues, consistent direction and spacing matter more than decorative quantity.

An optional soft, offset dark shape below the fish can suggest depth without modelling water physics. Do not trace the whole silhouette closely, which produces a sticker border. Keep it smaller, lighter and displaced, or omit it if it adds less than it distracts.

## Troubleshoot a floating-paper appearance

Hide ripples and shadows first. If the fish is flat, correct its broad front, narrow stalk and side shading; water marks cannot supply body volume. Restore the surface layer and remove overly bright or dense reflections that fragment the contour. One soft crossing may be enough.

If the patches dominate, reduce their saturation or shrink the largest one before fading everything. Preserve grey modelling in the white body. For a reversed turn, rebuild inner and outer contours before placing patches rather than copying the same red layout onto a different pose.

## Review and plan the next study

At small size, check swimming direction; at normal size, check patches wrapping around the back; close up, repair only fin roots and eye connections. If the fish works without ripples, do not cover it with scales merely for detail. Preserve a clearer centre and simpler extremities.

Name the reflection-free preview and final PNG separately, retaining the native body structure. Next, keep the fish fixed and change only water-surface values to compare depth cues. Changing the body and patches simultaneously would obscure whether the improvement came from water treatment or new proportions.

## Related tutorials and sources

[Edges and backgrounds in transparent materials](<https://allluckly.cn/en/guides/aquarell-glass-bottle/>), [Water and foam layers](<https://allluckly.cn/en/guides/aquarell-ocean-foam/>).

Checked on October 26, 2026 against the [official Aquarell App Store listing](<https://apps.apple.com/cn/app/id1591340577>) and [Apple’s public version lookup](<https://itunes.apple.com/lookup?id=1591340577&country=cn>): version 1.0.5, requiring iOS / iPadOS 15.0 or later. This is a hand-drawing and artwork-organisation exercise; sizes and colours are suggestions. Controls depend on the installed version. No step-by-step device testing is claimed.