Should art print collecting include a mat?

The functional role of a mat in art print collecting

A mat (or mount in UK terminology) serves three primary purposes: physical protection, optical balance, and long-term preservation. The Fine Art Trade Guild defines a conservation-grade mat as one made from 100% cotton rag or alpha-cellulose, acid-free to pH 7.5–8.5, with a minimum 1.4 mm thickness at 4-ply weight. This barrier prevents the print from adhering to the glazing over time—a risk amplified in humid climates or with pigment-based inks.

Standard mat widths for prints range from 5–10 cm (2–4 in), with 7.5 cm (3 in) being the most common for 30x40 cm (12x16 in) to 50x70 cm (20x28 in) works. Larger formats (A1 and above) may use proportional increases up to 12 cm (4.75 in). The overmat—extending beyond the print’s edges—ensures the glass never touches the inked surface, even with seasonal expansion of the paper.

Material specifications for archival standards

For pigment-ink giclée prints on cotton rag (250–310 gsm), the mat must match the paper’s longevity. Acid-free, lignin-free cotton museum board (e.g., Bainbridge Artcare or Crescent RagMat) is the baseline, with an 8-ply thickness (3.2 mm) recommended for prints exceeding $800 in value. Budget alternatives like alpha-cellulose boards (e.g., Nielsen Bainbridge’s Alphamat) suit open-edition prints under $400 but degrade faster under UV exposure.

Color selection follows conservation logic: white or off-white (e.g., Bright White #9900 or Warm White #9902) reflect light evenly without optical distortion. Black core mats hide imperfections in the cut but require UV-filtering glazing to prevent fading of the print’s margins. The American Institute for Conservation notes that even "archival" colored mats (e.g., deep blues, reds) contain dyes that may migrate—restrict these to secondary mats behind the primary.

Resolving the complexity of framing decisions

The underlying concern—that framing involves irreversible choices—is addressed by adherence to the two-tiered approach used by institutional framers. First, the primary mat (directly adjacent to the print) must be 100% cotton rag, hinged with Japanese tissue and wheat starch paste (reversible, per Tate’s guidelines). Second, the fillet or spacer (a thin strip between the mat and glazing) maintains a 1.5–3 mm gap to prevent condensation.

Glazing selections simplify further:

• Standard glass (2 mm): For prints under $300, with a UV-blocking additive (e.g., Tru Vue’s Conservation Clear, 70% UV protection).
• Acrylic (3 mm): Lightweight, shatter-resistant, with 99% UV protection (e.g., Optium Museum Acrylic); required for prints over 60x90 cm (24x36 in).
• Anti-reflective glass (2.5 mm): Etched or coated for glare reduction (e.g., Artglass AR 70), adding 30–50% to cost but essential for high-gloss pigment prints.

Proportional guidelines for visual equilibrium

Mat widths scale with print size to maintain the 3:5:8 ratio (print:mat:frame) preferred by galleries. For example:

• 30x40 cm (12x16 in) print → 5 cm (2 in) mat → 2.5 cm (1 in) frame.
• 50x70 cm (20x28 in) print → 7.5 cm (3 in) mat → 3 cm (1.2 in) frame.
• A2 (42x59.4 cm / 16.5x23.4 in) print → 6 cm (2.375 in) mat → 2.5 cm (1 in) frame.

The bottom mat border is typically 1–1.5 cm (0.5 in) wider than the sides and top to create a visual "anchor," per the Fine Art Trade Guild’s framing manual. This asymmetry counters the optical illusion of a print appearing to sag when centered. For diptychs or triptychs, unified mat widths (e.g., 5 cm across all pieces) preserve cohesion, while varying colors (e.g., white for the primary print, warm white for secondary) denote hierarchy.

Cost considerations for long-term value

Prices for conservation framing adhere to material and labor benchmarks:

• Open-edition prints (under $300): $150–$250 for a 30x40 cm (12x16 in) frame with 4-ply cotton mat, standard glass, and acid-free backing.
• Limited-edition giclées ($800–$2,500): $350–$600 for a 50x70 cm (20x28 in) frame with 8-ply rag mat, UV acrylic, and French cleat hanging system.
• Oversized works (A1 or larger): $700–$1,200+ for custom joinery, 3 mm Optium Acrylic, and reinforced backing to prevent warping.

Labor accounts for 40–60% of the total, with mat cutting ($25–$50 per opening) and hinging ($40–$80) as the most time-intensive steps. Pre-cut mats reduce costs by 20% but limit customization. For framed art print collecting, allocate 20–30% of the print’s value to framing—a $1,000 print warrants a $200–$300 frame to meet archival standards without overcapitalization.