Question 1

What is organoclay used for in printing ink?

Accepted Answer

In printing inks, organoclay functions as a thixotropic rheology modifier that: prevents pigment and filler hard-settling during storage (anti-settling); controls ink body and tack at rest vs. on press; reduces ink misting (ink fly) at high printing speeds by increasing the body and stringiness of the ink film; and improves dot definition by providing rapid viscosity recovery after the printing nip. Effective at 0.5–2.0 wt% in solvent-based and oil-based ink systems.

Question 2

What is ink misting and how does organoclay prevent it?

Accepted Answer

Ink misting (also called ink fly or flying) occurs at high press speeds when ink filaments stretching between rollers or between plate and substrate break into fine airborne droplets. Organoclay reduces misting by increasing ink body (gel strength) — raising the minimum stress required to form droplets and making ink filaments more cohesive before they break. At web offset speeds above 10,000 rpm, organoclay at 0.5–1.0 wt% measurably reduces misting and pressroom contamination.

Question 3

Which organoclay grade is best for offset printing ink?

Accepted Answer

For oil-based offset and lithographic inks (vegetable oil, mineral oil, aliphatic solvent systems): CP-34, CP-40, CP-EL, or CP-GL (conventional grades with polar activator; strongest anti-settling and body control). For lighter-color offset inks where color impact matters: CP-10 or CP-10A (white powder, easy-dispersing). For wide-polarity solvent offset inks: CP-388 or CP-MPS. Treat rate: 0.3–1.5 wt% depending on pigment load and target body.

Question 4

Can organoclay be used in UV inks?

Accepted Answer

Yes. Organoclay can be used in UV-curable inks where the monomer base has low to medium polarity (acrylate monomers, oligomers). Recommended grades for UV inks: CP-388, CP-MPS, or CP-MPZ (wide polarity range, easy-dispersing). These grades provide thixotropy and anti-settling in UV monomer systems. Note: compatibility testing is required for each specific monomer/oligomer combination, as very high-polarity UV systems may require different grades.

Question 5

How do I add organoclay to printing ink?

Accepted Answer

Preferred method: add organoclay at the milling stage — combine with resin/varnish/solvent blend in the dissolver, optionally add polar activator (for conventional grades), disperse at high shear (Cowles, 15–20 min), then mill with pigment in bead mill, three-roll mill, or ball mill to target fineness (Hegman 7–7.5). The milling shear simultaneously completes organoclay activation and pigment dispersion. For easy-dispersing grades, post-addition at the let-down stage is also effective.

Question 6

What is the treat rate for organoclay in printing ink?

Accepted Answer

Typical treat rate for organoclay in printing inks: 0.3–0.8 wt% for light-pigment, standard body inks; 0.5–1.5 wt% for heavy-pigment or high-body inks; 0.5–2.0 wt% for screen printing inks requiring strong thixotropy. Start at the lower end and measure ink body (tack meter or viscometer) to confirm target rheology before increasing dosage.

Function	Mechanism	Print Quality Impact
Anti-settling	Platelet gel network suspends dense pigments at rest	Consistent color strength; no hard-cake in can; stable ink fountain
Body / tack control	Gel structure builds low-shear viscosity (body) and controls tack profile	Clean ink transfer; predictable dot gain; reduced picking and setting time
Anti-misting	Higher ink body raises minimum stress for filament breakup; more cohesive ink film	Reduced ink fly at high web speeds; cleaner pressroom; less substrate contamination
Flow and leveling	Thixotropic recovery after nip allows ink to level on substrate before gelling	Smooth print, good gloss, defined dot edges

Ink Type	Base System	Organoclay Application	Priority
Offset / lithographic inks	Vegetable oils, mineral oils, aliphatic solvents	Anti-misting, body, anti-settling	High
Gravure inks	Solvent-based (toluene, MEK, ethyl acetate)	Anti-settling, thixotropy	High
Screen printing inks	Solvent / UV monomer	Strong thixotropy, body, anti-settling	High
Letterpress inks	Oil-based	Body control	Moderate
Flexographic inks (solvent)	Solvent-based	Anti-settling, low thixotropy	Moderate
UV-curable inks	Acrylate monomers (non-polar to medium)	Thixotropy, anti-settling	Moderate

Ink System	Typical Base	Recommended Grade	Dosage
Oil-based offset / litho	Vegetable oil, mineral oil, aliphatic	CP-34, CP-40, CP-EL, CP-GL	0.3–1.2 wt%
Aromatic solvent inks	Toluene, xylene	CP-10, CP-10A, CP-34, CP-40	0.3–1.0 wt%
Ketone / ester inks	MEK, ethyl acetate	CP-APA, CP-MP, CP-EDS	0.3–0.8 wt%
Alcohol-containing inks	Ethanol / propanol blends	CP-APA, CP-MP	0.3–0.8 wt%
Screen printing (solvent)	Medium-polarity solvents	CP-10, CP-APA, CP-MP	0.5–2.0 wt%
UV-curable inks	Acrylate monomers	CP-388, CP-MPS, CP-MPZ	0.3–1.0 wt%
Wide-range / mixed solvent	Any	CP-388, CP-MPS, CP-MP10	0.3–1.5 wt%

Grade	Type	Key Advantage for Inks
CP-34	Conventional	Highest gel strength; excellent anti-settling; wide polarity
CP-40	Conventional	Same as CP-34; broad solvent compatibility including aliphatic
CP-10 / CP-10A	Easy-dispersing	White powder; no yellowing in light-colored inks; good anti-misting
CP-APA	Self-activating	No polar activator needed; high-polarity solvent inks (ketone, ester)
CP-MP	Easy-dispersing	Fine particle ≤10 μm; high purity; excellent for transparent gel inks
CP-EDS	Easy-dispersing	Ultra-fine ≤10 μm; aromatic and no-solvent UV inks
CP-EZ10	Enhanced easy-dispersing	Explicitly recommended for ink; fine particle; anti-settling

Organoclay for Printing Ink

Functions of Organoclay in Printing Inks

Applicable Ink Types

Grade Selection by Ink System Polarity

Recommended Grades — Key Properties

Incorporation Methods

Milling Stage (Preferred)

Post-Addition (Let-Down Method — Easy-Dispersing Grades)

Anti-Misting in Detail

Frequently Asked Questions

Request Ink-Grade Organoclay Samples & Technical Data