← Medium
MEDIUM
Turpentine & OMS
Solvents are not mediums in the strict sense — they thin paint and clean brushes rather than modifying its film-forming properties. But they are essential companions to all other oil mediums. Turpentine is the traditional artist solvent — powerful, able to dissolve resins, but strong-smelling and requiring ventilation. Odourless Mineral Spirits (OMS) — with Gamblin's Gamsol as the artist standard — performs the same function with far less fume and is safer for regular studio use. Never use hardware-grade turpentine or white spirit — impurities affect paint films.
Properties ▾
Turpentine — Base: Distilled pine resin / Strength: Powerful / Fumes: Strong — ventilate
OMS (Gamsol) — Base: Refined petroleum / Strength: Moderate / Fumes: Minimal
Effect: Thins paint, speeds drying, cleans brushes
Fat-over-lean: Solvent-thinned layers are the leanest — use in first layers only
Film effect: Too much solvent alone weakens the paint film
Techniques ▾
First lean layer
Thin paint heavily with solvent for the first layer of an indirect painting. This creates the leanest possible ground. Allow to dry completely before adding oil-rich layers above.
Brush cleaning: Keep a jar of OMS for brush cleaning during a session. Paint settles to the bottom, allowing the clean solvent on top to be poured off and reused — economical and practical.
Medium dilution: Add a small amount of solvent to linseed oil or stand oil to reduce viscosity for brushing out. The classic proportions are 1 part stand oil to 1 part turpentine for a basic glazing medium.
Avoid overuse: Using solvent alone — without oil — to thin paint for multiple layers creates a weak, chalky paint film. Always combine with a drying oil in anything above the first layer.
Brush cleaning: Keep a jar of OMS for brush cleaning during a session. Paint settles to the bottom, allowing the clean solvent on top to be poured off and reused — economical and practical.
Medium dilution: Add a small amount of solvent to linseed oil or stand oil to reduce viscosity for brushing out. The classic proportions are 1 part stand oil to 1 part turpentine for a basic glazing medium.
Avoid overuse: Using solvent alone — without oil — to thin paint for multiple layers creates a weak, chalky paint film. Always combine with a drying oil in anything above the first layer.
The "fat over lean" rule starts with solvent. A thin, solvent-washed first layer is the leanest thing you can put on canvas. Everything above it must contain progressively more oil. Breaking this rule — painting a lean layer over a fat one — is the primary cause of cracking in oil paintings.
Works in ekphra ▾
No works found yet — artists using Turpentine & OMS will appear here.
Notes
▾
No notes yet.