Paint WIP

Paint and Paint Properties for Hobby Model Kits and Miniatures (WIP 5/24/2025)

Overview

Painting and finishing model kits involves selecting and applying appropriate primers, putties, and paints. Understanding the chemistry, application methods, and tools available for hobby painting is essential for achieving smooth, durable, and visually accurate results. This article summarizes best practices and relevant theory for model priming, painting, and surface preparation, particularly for hobbyist modelers.

Basics

Painting an object usually requires the following steps:

A primer is applied to the model, allowing paint to adhere to surfaces it normally has trouble with. 1-2 layers.
A base coat is applied
Paint layers are added as necessary

Paint Composition and Mediums

Paint consists of two main components:

Pigment: The colorant, suspended in a medium.
Medium: The liquid binder that delivers the pigment to a surface.

Different mediums produce different types of paints:

Acrylics: Water-based, using acrylic polymer as a binder.
- Matte medium is an unpigmented acrylic medium used to modify paint characteristics without compromising color vibrancy, unlike water which can dull pigments.
Lacquers: Solvent-based, fast-drying, and bond physically to surfaces.
Hybrid Acrylics: Alcohol-based paints that behave like lacquers but can be thinned with water or lacquer thinner.
Enamels: Oil-based paints using alkyd binders.

Primer Use and Recommendations

Primers create a base layer that helps paint adhere to surfaces and reveal surface imperfections. Key recommendations for hobbyists:

Best: Mr. Surfacer 1500 thinned 1:1 with Mr. Color Leveling Thinner via airbrush.
Very Good: Mr. Surfacer or Tamiya spray can primers.
Acceptable: Hobby-grade aerosol primers.
Not Recommended: DIY/home improvement spray primers due to incompatible solvents.

Color selection: Grey filament highlights defects, white primers for bright paint colors, and black under metallics for deeper tones.

Brush-on primer tips (e.g., Vallejo Acrylic Primer):

Shake vigorously, eliminate air bubbles before application.
Use synthetic brushes.
Thin with a damp brush, allow at least 1 hour between coats.
Note: White and grey primers have poor pigment density; black covers better.

Airbrush and Lacquer Use

Lacquers (e.g., Mr. Color, Tamiya LP) offer professional-level finishes but require:

Proper ventilation and a respirator due to VOCs.
Not suitable for hand brushing—each stroke can reactivate the prior layer.

Advantages of lacquer:

Fast curing and durable bond to plastic.
Fine pigment size allows use in detail airbrushes.
Versatile thinning ratios and finish tuning.

Disadvantages:

Health risks from VOCs.
Highly flammable.
Difficult hand-brushing behavior.

Paint Layering and Color Theory

Acrylic paints are semi-transparent. Effective layering uses:

Black base coats for metallic or dark shades.
White base coats for bright, vibrant colors.

High pigment paints require fewer layers. Understanding how light interacts with layers improves depth and finish quality.

Artist-Grade Acrylic Paints

Artist acrylics offer higher pigment density and customizable mixes:

Recommended brands: Winsor & Newton Professional Acrylics, Golden Fluid Acrylics, Daler Rowney System 3, Arteza (lower density, budget-friendly).
Matte medium improves flow and transparency without diluting color.
Paint can be customized to match hobby paint ranges using color mixers.

Matte Topcoat: Must be sprayed; no brush-on equivalents available.

Resource Links:

Putty Use for Surface Smoothing

For FDM print smoothing:

Acrylic putties like Vallejo are recommended over solvent-based types (e.g., Tamiya). Apply with a Q-tip or paper towel dipped in isopropyl alcohol (IPA), which softens and smooths the surface.
Recommended tools: Stainless steel carving sets from hardware stores such as Harbor Freight.

Google Sites

Report abuse