How to Draw GLASS in Clip Studio Paint


Hi! My name is Shani and In this tutorial I'd like to show you my favorite tricks and techniques to help you create the illusion of transparency like I did in the drawing below.

Transparent items can be very confusing to draw.
I mean - how can you possibly draw something if it doesn’t have any color?

the first part of this tutorial will explain the basics of drawing glass and the second part will expand and put those rules to action by painting a mermaid inside a bottle.

Basics of Drawing Glass

Before we start drawing, lets just make sure we are on same page
When light can pass through an item, that means it has transparent qualities.
The more light is able to pass through the more transparent an object is.

Examples of transparent items: glass, water, and air.
materials that allow some light to pass through them are called translucent, If an object does not allow any light to pass through it then it is opaque.

You can create the illusion of transparency in your drawings if you observe how light, shadow, reflection and value behave on transparent objects under different environments.

Lets get started!

transparent objects usually have lower opacity.
Opacity is the extent to which something blocks light. when You draw digitally,You can change the opacity of layers, brushes filters, and effects.


Value defines how light or dark a given color or hue can be. Values are best understood when visualized as a scale or gradient, from dark to light.
When shades of similar value are used together, they also create a low contrast image.

The more opaque an object is the more it blocks light. because of this, when we look through transparent objects like glass the color value of what you see through it will be lower and have less contrast.

Let me show you an example:


When sketching transparent items I recommend to use a reference or to study an object that looks similar to what your'e trying to draw. observing is key to a successful sketch!

Try using general shapes like ellipses to guide you and help define the general 3D shape of the object. try to see where the object has different planes and where it curves.

glass is usually the most visible where it is thickest and least visible where it is hollow, so try adding lines in areas of the object that are thicker- the bottom of the glass or the lip, detailing, zarfs and handles.

after your'e done with the sketch, you'll want to move on to adding a background, shadows highlights and reflections.

Note that glass reflects the light around it and usually has very defined highlights.

For highlights I recommend using a hard-edged brush.
For the shadow, try using a mix if soft and hard brushes.

I'll explain and expand more on this steps in the next part of this tutorial.

here is a guide if you're not sure about the difference between this types of brushes:

like other objects Glass also casts a shadow.
Since glass it is transparent the overcast shadow mirrors the highlights and shadows of the object- it will be lighter where there are highlights and darker where there are shadows.

In the second part of this tutorial I will demonstrate how you can use the free transform tool to achieve this effect.

Now that we are done with the basics


Step 1: Sketching and Line Art

Create a new A4 size canvas, make sure you set the resolution at 300dpi.

Using the pencil tool I start off by sketching my drawing and the object I want to make transparent. I decided to draw a cute little mermaid inside a corked bottle.

When sketching transparent items- keep your lines minimal while still paying attention the general shape, the different planes and curves. Don’t forget this object is 3D so we can see the back side of it as well!

I usually keep my drawing as a very detailed sketch so feel free to add line art to your drawing to match your style.

Step 2: Coloring Solid Objects and Characters

After I finish sketching, I paint anything that is not transparent. In this case I added base color and shading to the mermaid and cork.

Step 3: Adding the Background

when an object is completely transparent it doesn't have a color of its own. Instead, it reflects the lights and colors around it.

So adding the background is a very easy way to make a transparent object be seen.
In a layer underneath the original sketch I add a background. Doesn't have to be anything too fancy! Even a simple background will do 🥰

Using the g-pen I add a base color, and on the same layer I start adding and layering different colors.

Once I’m satisfied with the color palette, I star blurring and blending everything together. You can achieve this in two ways- using the blur tool

or the Gaussian Blur (which you can find by going to filter> blur> Gaussian Blur.

Here is a simplified version of the process:

And here is the progress on our drawing.

Use the finger tip tool with long downward strokes to create the illusion of a table/surface.

Step 4: Base Color

In a new layer using a hard-edge brush, fill in the transparent item with a light color.

clean the edges as needed.

TIP : if you want to make sure you only color ONLY inside the lines
use the wand tool on your lineart layer and select all areas your object.
press CTRL+SHIFT+I to invert the selected area, you now have the entire object selected.
go to a new layer and start filling paint with no mistakes :)

When done coloring, set it to a lower opacity. (I lowered mine to 18%)

The more transparent an object is the lower you should set the opacity at this stage.
If your glass has color or is tinted- use a base color that matches it and lower its opacity.
(for example a red cup will have a red base)

Step 5: Create Shadows

Now onto for the fun part!

To start shading first decide where the light in your drawing is coming from.
Picking a light source is important in order to understand how the light will hit and reflect off the surface.

Using a reference, I decided the light in this piece comes from behind the bottle.

shading and highlighting requires delicately building layers with low opacity on top of each other.

open a new layer above our base color but below the line art.
On this layer I start by adding in the darkest areas.
Use the Lasso tool to first block out the area that is darkest.
Fill it using the G-pen brush and a darker shade (I used a dark blue)
Continue adding brush strokes and patches of color until satsified but make sure to leave a lot of areas untouched.

When adding in shadows Its important to follow the shape and curves of the object.

If you're not sure where to color-
We usually see shadow at the edges or walls of a hollow transparent object because that is where the object is thickest and blocks more light.

If you look closely at a cup or a bottle, areas like the bottom, holders, zarfs, the “neck” of the bottle are thicker and narrower so they usually have more shadows and reflect more light.
Areas like the body of the bottle are wider and hollower so they let more light through and create less shading.

Note that the light source and surrounding environment can affect highlights and shadows.

If there is no clear light source- try shading areas that are thicker and also areas where two objects connect- like the neck and body of the bottle, the bottom of the bottle and the table.

next, use the blur tool (I use a smaller size brush for the blur then the one I use to fill the color)

blur a few of the hard edges to create a softer effect. Do NOT blur everything! Try to keep at least a few harder looking edges to create the glass-like effect.

Set the layer to a lower opacity (I set mine at 30%) and change the blending mode to multiply.

Step 6: Add Highlights

Transparent objects usually have a vey hard-edged highlight.

in order to achieve this Create a new layer.

Again using a hard brush (I used G pen) sketch out the highlights. Use different brush direction and strokes that follow the natural shape of the item.

For example this bottle has a very elongated shape so I used long straight lines and the added more shapes to define the volume. I also added smaller lines and dots to create more shine.

TIP: Never shade or highlight with pure black or white, try using very light or very dark saturated colors like light green/yellow and dark blue/purple

Set the layer blending modes soft light. Duplicate the layer with this effect for more dramatic results.

Play around with the layer setting for different effects! Different blending modes like: add (glow)/overlay/ pin light etc.. can all create beautiful glow-y results.

Repeat/fix steps 5&6 of shading and lighting until satisfied.

NOW you can stop here for a simplified look OR you can continue the fun by...

Step 7: Adding reflection

Using the eyedropper tool pick colors from the background and solid objects like the mermaid.

Next, use a softer brush to add reflections with this colors. I used the Gouache brush because it has low opacity and a slight texture.

turn the brush into an eraser by clicking the square under the color slider and erase parts of the color.

I suggest adding each different color on a seperate layer.

repeat this step and keep layering different colors. lower the opacity of each layer as needed.
alternatively, you can set the layer mode to "screen" to get a lower opacity.

add even more shading around the cork and bottom of the bottle on a layer set to multiply.


On a new layer, using a small hard brush paint the edges of the water. Anywhere the water touches another surface add small circular lines just to give a hint that there is reflection from the water there.

Next draw in small bubbles on a layer set to add (glow). For this step I drew small bubbles with the g-pen brush and also with a special bubble brush I downloaded from the clip studio paint assets.

Add tiny rays of light with turquoise.
I set my layer to "overlay" and used a soft brush to add long diagonal lines.


Go the the layer where you painted the character's base color.
Select the fin with the lasso tool.
Cut and paste it on a new layer (CTRL+X CTRL+V), lower the layer opacity to 50%.

Add another layer on top, draw detailing and highlight with a soft brush.

Step 8: glow and final touches

In order to create the cast shadow, first you'll need to finish ALL your shadows and highlights.

Add glow around the glass Using white or a very light color. set the layer to “soft light” or “add (glow)”.

blur outside edges a bit.

Step 9: Overcast Shadow using Free transfrom

The cast shadow of a hollow transparent object usually resembles the object's transparency: transparent in the middle and opaque at the edges.

To create the overcast Shadow first go to layer>flatten image
now all your layers are merged to one.

Then select the bottle using the lasso tool.
Copy the selected area and undo the steps until all the layers return.
paste your selection on a new layer
set this layer at the very top of all layers.

Change the layer blending mode to soft light or overlay or screen.

Using the free transform tool (ctrl+shift+t or edit>transform>free transform)
Drag the selection down and pull it to create a reflection.

make sure the angle is opposite to where your light source is coming from, so if my light comes from behind the bottle, the shadow will go forward toward the viewer.

press OK to finish transforming.

highlight the edges with a very small white hard-edge brush.
blur the middle a little and.. Voila! you've got yourself an overcast shadow!

Step 10: color correcting

Go to Layer> New color correction layer> Color Balance

Adjust until you like the color palette.



and that is the final result!

I hope you enjoyed reading this tutorial as much as I did creating it.

Now it's your turn to go have fun drawing transparent items!



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