HP Orange 3545 — Pigment Orange 13 (PO13) for Offset & Gravure Printing Inks | Honor Pigments

Technical Information

What Is PO13

Pigment Orange 13 (CAS 3520-72-7, CI 21110) is a disazopyrazolone organic pigment whose chromophore — two azo bridges linking pyrazolone terminal groups into a planar conjugated system — produces a bright, transparent yellowish orange with color strength that handily outperforms inorganic orange pigments. It is the volume-standard organic orange across the printing ink, industrial coating, and plastics compounding industries, valued not for pushing any single performance parameter to its limit, but for delivering balanced coloristics, reliable dispersion, and predictable batch-to-batch behavior in the moderate thermal and chemical conditions that describe the majority of real-world manufacturing. PO13 is the pragmatic choice: it does the work that needs doing at a pigment cost that keeps the finished formulation competitive, without the over-engineering premium of higher-performance orange chemistries that most applications never actually require.

Why Choose HP ORANGE 3545

HP ORANGE 3545 is the benchmark grade in Honor Pigments’ PO13 range — the standard from which the specialized variants derive. Where HP 3434 is tuned for ink and coating systems requiring optimized dispersion across solvent and aqueous vehicles, and HP 3357 is engineered for plastics applications where low-warpage behavior in polyolefins is the critical specification, HP ORANGE 3545 is the general-purpose reference: the grade that performs capably in sheet-fed offset inks, solvent-based industrial coatings, and general-purpose plastics coloring without specialization in any single direction. For the formulator who needs one reliable orange that covers a mixed production environment — say, an offset ink line alongside a solvent-based paint batch — this is the consolidation choice that avoids the cost and inventory friction of stocking separate grades. The shade is a neutral mid-orange, the workhorse position in the PO13 color space, blending freely with yellows for warmer tones and reds for deeper orange without the pigment imposing its own directional bias. HP ORANGE 3545 is not the grade for the demanding edge case. It is the grade for everything else — and everything else is most of the market.

Key Features

• Balanced all-around performance for mixed-production environments: this grade delivers competent dispersion, color development, and shade stability across offset inks, solvent-based coatings, and general-purpose plastics — allowing a manufacturer with diverse output to stock a single orange pigment rather than managing separate grades for each production line, which reduces purchasing complexity and incoming QC workload.
• Neutral mid-orange shade that serves as a reliable blending anchor: positioned at the center of the PO13 color family, HP ORANGE 3545 accepts both yellow and red letdown adjustments without resistance, giving the color matcher a predictable starting point that cuts the reformulation cycles needed to lock in a target shade across different binder systems.
• Low-misting rheology for clean sheet-fed offset press operation: the pigment’s surface characteristics contribute to stable ink-water balance and reduced ink misting at high press speeds, which means fewer press stops for blanket washes, lower ink waste, and a cleaner printroom environment — a direct operational benefit that compounders and paint formulators never see but that printers value immediately.
• General-purpose migration resistance for standard plastics applications: HP ORANGE 3545 provides adequate migration fastness for polyolefin and PVC coloring at typical processing and service temperatures, making it a practical choice for injection-molded consumer goods, extruded profiles, and cable sheathing where the end-use conditions do not demand the extreme non-migration performance of a dedicated plastics-grade pigment.
• Traceable batch quality with spectrophotometric release documentation: every production lot of Pigment Orange 13 (CAS 3520-72-7, CI 21110) is tested against the master standard under D65 and ships with a Certificate of Analysis recording shade, color strength, dispersibility, and particle size data — providing the formulator with documented incoming quality evidence rather than an unverified supplier claim.

Recommended Applications

Primary: Sheet-fed and web offset printing inks where clean mid-orange shade, low misting, and stable ink-water balance support uninterrupted high-speed press operation; solvent-based industrial and decorative coatings — alkyd, acrylic, and polyurethane systems — requiring bright, transparent orange with predictable color development; general-purpose polyolefin and PVC coloring for injection molding, extrusion, and cable sheathing where standard migration resistance is adequate for the application.

Secondary: Water-based flexo and gravure inks — subject to dispersant optimization for the aqueous vehicle; powder coatings where the pigment must survive the bake cycle without shade shift; decorative artist-grade and DIY colorants requiring a vibrant, lightfast orange for interior service.

Shade selection within the Honor PO13 range: HP ORANGE 3545 is the benchmark — neutral mid-orange with balanced all-around performance. For formulators whose application is predominantly ink and coatings, HP 3434 delivers optimized dispersion and broader solvent compatibility in those media. For plastics compounders where low-warpage behavior in semicrystalline polyolefins is the make-or-break specification, HP 3357 provides a dedicated solution. The four-grade PO13 family forms a deliberate coverage map: EARTH COLOUR ORANGE for cost-first commodity work, HP ORANGE 3545 as the all-purpose benchmark, HP 3434 for ink and coating specialization, and HP 3357 for plastics precision. Contact technical support for a side-by-side evaluation of the grade that best matches your process conditions and cost-performance balance.

Technical Data

Frequently Asked Questions About PO13

PO13 3545 vs 3357 vs 3434 — which HP Orange grade fits my production?

The choice turns on what your production lines actually demand. HP ORANGE 3545 is the benchmark — a balanced, general-purpose Pigment Orange 13 (CAS 3520-72-7, CI 21110) that performs capably in offset inks, solvent-based coatings, and general-purpose plastics. If your facility runs a mix of applications and you want one orange to cover them without over-specifying, start here. HP 3434 is the step up for dedicated ink and coating operations: optimized dispersion across solvent and aqueous vehicles, broader binder compatibility, faster color development. HP 3357 is the plastics specialist — engineered for low-warpage behavior in polyolefins where nucleation-driven dimensional distortion is a rejection risk. The rule of thumb: multi-process → 3545, ink-and-coating dominant → 3434, plastics-first → 3357. For operations running all three, a split between 3545 and 3357 often provides the best coverage at the lowest total inventory cost.

Low-misting PO13 for high-speed sheet-fed offset printing?

Ink misting at high press speeds creates a cascade of problems: blanket contamination, increased wash frequency, elevated ink consumption, and airborne pigment in the pressroom. HP ORANGE 3545’s surface treatment and particle characteristics are designed to support stable ink-water balance in sheet-fed offset systems, which directly reduces mist generation at the printing nip. The practical result for the printer is fewer press stops for blanket cleaning, lower ink waste per thousand sheets, and a cleaner working environment — all contributing to higher net throughput and lower cost per impression. For the ink manufacturer formulating a process-orange or spot-orange offset ink, this grade’s rheological predictability means the formulator can hit the target tack and flow curve without compensating for pigment-induced viscosity drift. HP ORANGE 3545 ships with an offset ink formulation guideline for first-time formulators to shorten the bench-to-press timeline.

Migration resistance of PO13 in PVC cable sheathing compounds?

PVC cable sheathing exposes pigment to plasticizer migration, elevated service temperatures, and long-term contact with adjacent materials — a combination that can extract poorly anchored organic pigments and cause visible blooming or contact staining. HP ORANGE 3545 provides adequate migration fastness for standard PVC cable and wire jacketing applications where the plasticizer system is a conventional phthalate or trimellitate type and the service temperature stays within the cable’s rated range. The disazopyrazolone molecule itself has limited solubility in common plasticizers, which is the fundamental migration barrier, and this grade’s particle engineering does not compromise that inherent resistance. For cable constructions with aggressive plasticizer loadings, extended high-temperature service, or direct food-contact-adjacent use, a migration test under the specific compound formulation is recommended. HP ORANGE 3545 is fit for the standard cable sheathing segment — which is where the majority of orange PVC compound consumption occurs.

Matching RAL 2004 Pure Orange with PO13 in powder coatings?

RAL 2004 Pure Orange is a saturated, mid-orange shade that sits squarely within the coloristic range of Pigment Orange 13 (CI 21110). HP ORANGE 3545’s neutral orange chroma provides a close starting point for RAL 2004 matching in powder coating systems, typically requiring only minor adjustment with an organic yellow or red to dial in the exact spectral target. The key consideration for the powder coating formulator is thermal stability through the bake cycle: PO13 tolerates the moderate cure schedules of standard powder coatings — typically 180°C to 200°C for 10 to 15 minutes — without the shade drift or strength loss that would push the finished coating outside the RAL tolerance band. For powder coaters producing architectural or industrial finishes that must meet RAL certification for project specification compliance, HP ORANGE 3545 provides a reliable coloristic foundation. A pre-production trial at the coater’s specific cure profile is recommended to confirm ΔE within the RAL tolerance before committing to full-scale production.

PO13 opacity and hiding power compared to inorganic orange pigments?

Pigment Orange 13 is a transparent organic pigment — it produces bright, clean color by transmitting and selectively absorbing light rather than scattering it. This is the fundamental optical difference from inorganic oranges like lead chromate or iron oxide, which derive their color from a combination of absorption and high refractive-index scattering that produces opacity. For applications where hiding power is the requirement — think single-coat industrial enamels or opaque signage inks — an inorganic orange provides inherently better coverage per mil of dry film thickness. The trade-off is in chroma: PO13 (CAS 3520-72-7) delivers a significantly brighter, more saturated orange than any inorganic alternative, which is why it dominates printing inks where transparency is an asset and brightness drives visual impact. HP ORANGE 3545 occupies the sweet spot where transparency and color purity are valued — offset process printing, transparent packaging inks, and glaze-type decorative coatings. For formulators who need opacity, combining HP ORANGE 3545 with a small loading of titanium dioxide or an opaque extender provides a practical middle path without switching to a duller inorganic orange.