21x33 Deep Blue / Midnight Blue Custom Mat for Picture Frame - Clean

In this review of the 21x33 Deep Blue / Midnight Blue Custom Mat from ArtToFrames the bottom line is simple: this mat is for anyone who needs a precise, archival-looking mount for a 17x29 photo without buying a whole frame. The reviewer found the construction and color accuracy to be the biggest reasons to buy - the mat is made from standard 4 ply material used in custom frame shops and is described as lignin-free and pH-neutral, so it both looks professional and helps protect artwork. It arrives cut to fit a 21x33 frame and the opening is accurately sized.

Key Features

• Standard 4 ply construction: The multi-ply board gives a substantial, gallery-style edge that improves presentation and resists warping.
• Archival materials: Lignin-free and pH-neutral composition helps preserve photos and prints for long-term display.
• Accurate opening: The mat is cut so a 17x29 photo fits; the actual opening measures 16.75x28.75 to allow for overlap and secure mounting.
• Frame compatibility: Sized to sit inside a 21x33 frame, making it a direct replacement when only the mat is needed.
• Color fidelity: The deep blue / midnight blue tone matches product images closely, delivering the expected aesthetic for classic or modern displays.
• Custom cuts available: The manufacturer offers custom opening sizes on request for nonstandard projects or precise composition needs.

Who It's For

This mat is aimed at hobbyists, photographers, and framers who want a professional-looking presentation without commissioning a full custom frame. Because it uses the same 4 ply board common in frame shops and is made from archival materials, it is well suited for preserving prints, photos, and limited editions.

It is not the best choice for someone who needs pre-mounted backing board, a complete frame, or an unusually shaped opening without requesting a custom cut. Buyers who need foam-core or heavyweight backing should look elsewhere, since this item is a mat only.

Pros & Cons

Pros

• High build quality from standard 4 ply material gives a finished, durable edge.
• Archival, lignin-free and pH-neutral materials protect artwork over time.
• Opening and outer dimensions are cut to predictable, accurate sizes for an easy fit in a 21x33 frame.
• Color and cut quality were praised by multiple customers for matching expectations.

Cons

• Mat is sold alone and the product does not include a frame or backing, so additional purchases are required for complete framing.
• One limitation is that the actual opening is slightly smaller than the nominal 17x29 to allow overlap, which some users must account for when arranging precise compositions.

Specifications

Brand	ArtToFrames
Outer size	21x33 in (fits 21x33 frame)
Nominal photo fit	17x29 in
Actual opening	16.75x28.75 in
Material	Standard 4 ply mat board
Conservation	Lignin-free and pH-neutral
Custom options	Custom opening sizes available on request

Our Verdict

The 21x33 Deep Blue / Midnight Blue mat is a smart, cost-effective choice for anyone needing a precise archival mat for a 17x29 photo. It delivers reliable cuts, true-to-photo color, and the conservation qualities expected from custom framing materials. Buyers who already have a frame or who plan to pair it with a separate backing will find it good value for the quality and fit.

Frequently Asked Questions

Will this mat fit a 21x33 frame?
Yes, the mat is sized to fit inside a 21x33 frame and is intended as a replacement mat for that frame size.

What is the actual photo opening size?
The actual opening measures 16.75x28.75 in so a 17x29 photo will overlap slightly for secure mounting.

Can I get a different opening size?
Yes, custom opening sizes are available upon request from the seller for nonstandard projects.