IEM design guide

Below we provide some useful information for choosing a perfect IEM design.

1. Choice of material: acrylic vs silicone









Hard, non-flexible

Very good

Very good




Semi-hard, flexible




Very high



Personal use

Professional use



Recessed sockets

Low-profile shell








Not recommended




Non-detachable variant only

Acrylic IEMs have certain advantages over silicone ones – they are more durable, easier to insert and remove. The first material is hard and does not flex, which means there’s no risk of breaking internal wiring. It also does not trap any moisture inside the shell which dramatically improves drivers’ life span.


Silicone tends to have a slight edge on comfort, but in our opinion, the difference is only really noticeable during long-lasting listening sessions. According to our customers, they also find silicone to offer slightly higher isolation. However, silicone IEMs require more attention to care and maintenance such as cleaning and proper-storing. We also recommend drying them using professional hearing aid dryers, which will extend their life and prevent moisture accumulation inside the shell.

For professional use (stage/studio) we recommend acrylic shells only!

Note: It is not possible to combine soft silicone canals with acrylic shell body.


2. Colors – directions for shell design

• Clear, Sky Blue and Black Transparent are our bestselling colors in both silicone and acrylic techniques.
• Clear canals always go well with transparent colors as they typically blend well together, creating almost gradient-like effect.
• Clear shells with Blue and Red transparent canals are popular choice for easy distinction between left and right earphone.
• Clear shells are great choice if you want the IEM to be the least visible in the ear.
• Black Solid (one piece) with White solid (second piece) creates nice contrast between left and right without being flashy.
• Blue and Purple go well with White (eg. Purple Transparent body and White Solid faceplates).
• Red and White go well with Black (eg. Red Transparent shell and Carbon Fiber faceplates).
• Black goes well with Gold (eg. Black Solid shells and faceplates with gold logos engraved).
• Silicone: Sky Blue matching color is Crimson Red Transparent
• Silicone: Dark Blue Transparent matching color is Red Transparent
• Acrylic: Blue Transparent matching color is Red Transparent
• Acrylic: White Transparent (custom color) matching color is Smoky Grey Transparent (custom color)


Try to avoid mixing Complementary colors unless you are perfectly sure about the effect you would like to get.

Please also remember that transparent faceplate color will be affected by the shell color. For instance, if you combine White Solid shell and Light Red Transparent faceplate, the plate will look pinkish and lighter than it normally would.

On the other hand, Opaque faceplates (such as Black Solid) will make a shell look darker. To illustrate this, if you choose Black Transparent body and Black Solid faceplates, the shell will not be very see-through.

Avoid choosing solid or metallic colors for canal parts as they create clear cut-off line on the shell and don’t blend well with transparent or opaque colors.

Play around with our in-store IEM designer as there are plenty of options you can choose from. You may also visit our Facebook gallery to check out or previous builds.

Still undecided? You can always leave the design at our hands or provide some clues for making your favorite design and we will create something special. You can also send us a direct link to a picture of an IEM and we will use that as inspiration for your design (please use Notes and Request field at the checkout).

3. General look of the IEMs

a) Internal wiring
By default, we use blue+silver wiring for left IEM and red+silver wiring for right IEM. If you want to change the wiring to all blue, all red or all silver please leave a note at the checkout.

b) Tubing
We use clear tubing as the only option for silicone IEMs.
Clear tubing is default option for acrylic IEMs, however upon special request we may make acrylic IEMs with blue, red or black tubing. If you wish to change tubing color, please specify that at the checkout.

Note: colored tubing comes in only one size and we can only use it for IEMs that incorporate that particular tubing diameter.
Note: colored tubing may be harder to clean due to lower transparency.

c) Serial Number
By default serial number is made Blue on the left and Red on the right ear piece. For right earpiece in Red colors we use Black filling by default. For left shell in Blue colors we use White filling by default. If you want to change the colors or leave the serial number unfilled with any color, please add a note when submitting an order.


Serial number is a mandatory part of each IEM.

d) Finish
Gloss finish is default finish for all of our products. It creates shiny, sleek surface. Majority of our customers decides for a glossy lacquer.
Both acrylic and silicone IEMs come with a gloss finish only.

Note:In case of silicone IEMs, gloss finish wears off and IEMs will lose its shine over time and will become more matte. That’s natural process for the material.

e) Detachable vs non-detachable cables
Most our customers choose a detachable cable system because it makes replacing cables easy in case of any malfunction or damage. You should also choose a detachable cable if you would like to use some third-party cables. Non-detachable option is available only for silicone IEMs.

Note: Custom Art cannot guarantee compatibility with third-party cables.

f) Artworks
Some simple graphics or text may be engraved on the faceplates of the IEMs.
More complex images will be printed. However, due to limitation with printing technique, please make sure to consult with us before placing an order and we will try to provide you the best solution for your design.

4. Disclaimers

Colors represented on this website or online store may vary due to differences in displays.

While we take pride in attention to details and always carefully manufacture our IEMs, please consider that each product is hand-crafted to the specific order. We go to great lengths to insure that each monitors leaving the lab meet our standards. However, because all IEMs are hand-build, there might be some imperfections in shell finish, such as small bubbles in shells or on faceplates.

None of visual imperfections (unless impacting user’s comfort, causing malfunction of the product or resulting in the overall design being different from the one chosen and confirmed by the Customer) can be a reason for return of a customized product.