Collector Glossary

A signed document that formally attests a work is genuine, typically stating the artist, title, medium, edition, and date. A COA carries weight only when it comes from a party with real authority — the artist, their estate, the publisher, or a recognized authentication service. Verify a certificate →

A letter, rather than a formal certificate, issued by an authenticator or dealer affirming a work or signature is genuine. Common in autographs and memorabilia; its value depends entirely on the credibility of the issuing authority.

The specific, unbroken sequence of documents and bodies that establishes a work as genuine — for example, a publisher COA plus a matching hologram plus a database entry. Chains are artist-specific and should never be mixed or substituted between artists. See how to spot a fake →

A unique identifier printed on a COA that ties the document to a single work and, ideally, to a verifiable registry entry. A number that can be checked against an official database is far stronger than one that cannot.

An uninked, embossed mark pressed into the paper — usually the mark of the printer, publisher, or workshop. Because it leaves a raised or recessed impression rather than ink, it is difficult to reproduce and serves as a subtle authentication feature.

A raised design created by pressing paper between dies, without ink. Embossing is used decoratively and as a publisher or authentication mark; you can often feel it with a fingertip and see it in raking light.

A small embossed or inked seal — historically borrowed from the East Asian tradition of the artist's or studio's stamp — identifying the printer, workshop, or collection responsible for a print.

Another term for an uninked, embossed stamp (a “dry” impression made without ink). Used interchangeably with blind stamp to describe a pressed publisher or authentication mark.

A holographic sticker or seal, often numbered, applied by a publisher or authentication body to deter counterfeiting. For some artists a matching hologram is a required link in the authentication chain; on its own, though, a hologram is only as trustworthy as the body that issued it.

Professional Sports Authenticator, a leading third-party grading and authentication company. Its PSA/DNA service authenticates autographs and memorabilia, issuing a serial-numbered certification that can be verified in an online database.

A widely respected third-party authentication service specializing in autographs and signed memorabilia. A JSA letter or sticker with a matching certification number is a recognized standard in the signed-collectibles market.

Beckett Authentication Services, a major third-party authenticator of autographs and memorabilia. Like PSA and JSA, Beckett issues verifiable certification numbers, and pieces carrying multiple respected letters generally command more confidence.

Zarelli Space Authentication, a specialist service that authenticates spaceflown and space-program artifacts and autographs. In a field crowded with reproductions, a Zarelli opinion is a benchmark for astronaut signatures and flown items. Read the Apollo 11 buyer’s guide →

The official authentication body for the artist Banksy. It is the only entity that issues genuine certificates for Banksy prints and screenprints; works without a valid Pest Control certificate are generally not accepted as authenticated on the secondary market.

A digital certificate-of-authenticity platform that pairs each work with a verifiable online record, letting a buyer confirm a certificate’s details rather than relying on paper alone. Look up a certificate →

Near-Field Communication: a small embedded chip or tag that, when tapped with a phone, links a physical object to a secure digital record of authenticity. Used by some publishers to tie a work to a tamper-evident, scannable certificate.

The documented ownership history of a work, from creation to the present. Strong provenance — gallery receipts, exhibition records, prior sales — supports authenticity and value; gaps in provenance are a reason for caution.

The fine-art term for a screenprint: ink is pushed through a fine mesh screen, one stencil per color, to build up an image. Serigraphs are prized for their dense, flat, saturated color. How to spot a fake print →

A printmaking method in which ink passes through a stencil on a mesh screen onto the paper below, using a separate screen for each color. “Silkscreen,” “screenprint,” and “serigraph” describe the same process. See the tells →

A print made on the principle that oil and water repel: the image is drawn on a stone or plate with a greasy medium, which holds ink while the blank areas hold water. True (hand-drawn) lithographs are original prints, distinct from photomechanical offset reproductions.

A commercial printing process in which the inked image is transferred (offset) from a plate to a rubber blanket and then to paper. Offset lithographs are typically reproductions produced in large quantities and are generally less valuable than original hand-pulled prints. A loupe often reveals a regular halftone dot pattern.

A high-resolution inkjet print made with archival pigment inks on fine-art paper or canvas. “Giclée” (from the French for “to spray”) denotes quality of output, not originality — the value depends on whether the work is a limited, artist-sanctioned edition or an open reproduction.

A relief printing method in which a raised, inked surface is pressed into the paper, often leaving a tactile impression. Valued for its craftsmanship and the subtle debossed bite of type and image.

Any print made from a raised surface, where the areas that carry ink stand above those that are cut away. Woodcuts, linocuts, and letterpress are all relief processes.

An intaglio process in which lines are bitten into a metal plate with acid; ink settles into the recessed lines and transfers to dampened paper under pressure. Etchings often show a plate mark — an embossed rectangle where the plate met the paper.

A relief print carved into a block of wood; the raised, uncarved areas take the ink. One of the oldest printmaking techniques, known for bold shapes and strong contrast.

A print that the artist has individually embellished by hand — with paint, spray, or collage — so that each impression in the edition is unique. HPMs typically command a premium over the standard edition because of that hand-worked variation.

A work combining more than one material or technique — for example, screenprint with hand-painting, collage, or drawing. The term signals that the piece is not a single, uniform process.

The precise alignment of each color layer in a multi-color print. Good registration keeps colors crisp and on-model; misregistration shows as offset edges or unexpected color fringes and can indicate a production flaw or a crude reproduction.

A method of simulating continuous tone using a grid of tiny dots. Under a loupe, mechanically reproduced images reveal an even halftone dot grid or a flower-like “rosette” pattern where the color screens overlap — a common tell that separates a printed reproduction from an original hand-pulled print.

The soft, feathered, untrimmed edge characteristic of quality handmade or mould-made paper. A genuine deckle is irregular and fibrous; a printed or die-cut imitation of one is a warning sign.

The complete set of impressions produced from the same image and released together. An edition is defined by its process, paper, and the total number of authorized impressions.

The total number of numbered impressions in an edition (for example, 500). Smaller edition sizes generally imply greater scarcity, though proofs outside the main run add to the true total produced. See how scarcity affects value →

An edition capped at a fixed, disclosed number of impressions, after which no more are made. The cap is what creates scarcity — provided the publisher honors it and does not later reprint.

A print with no fixed limit on the number of impressions produced. Open editions are usually more affordable and, because they are not scarce, tend to hold less resale value than limited editions.

The fraction written on a print — such as 42/500 — where the first number is that impression’s place in the sequence and the second is the total edition size. The numbering does not indicate print order or quality; it simply catalogs the edition.

An impression outside the main numbered edition, traditionally reserved for the artist. Marked “A/P” or “E/A,” APs are usually few in number and can carry a premium because of their association with the artist.

An impression set aside for the printer or workshop as a record of the collaboration. Marked “P/P,” printer’s proofs are scarce and, like artist proofs, sit outside the numbered edition.

French for “not for sale.” HC impressions were historically produced for exhibition or promotional use outside the commercial edition. They are marked “H/C” and are typically limited in number.

French for “good to pull.” The single approved proof the artist signs off on to set the standard for the entire edition — the reference the printer matches every impression against. Usually unique, and historically significant.

An impression pulled while the artist is still developing the image, often showing color or compositional differences from the final edition. Trial proofs are usually unique or very few, documenting the creative process.

A print bearing both the artist’s hand signature and its edition number, typically in pencil. A hand-signed and numbered impression generally carries more value and confidence than an unsigned or plate-signed one.

A written assessment of a work’s physical state, noting any flaws such as creases, tears, toning, foxing, or restoration. A thorough condition report is essential before buying, since condition strongly affects value.

Small brown or rust-colored spots on paper, caused by age, humidity, and impurities. Foxing is a condition defect that can sometimes be reduced by a conservator but generally lowers value.

An overall yellowing or darkening of paper over time, usually from light exposure, acidic materials, or age. Light, even toning is common in older works; pronounced toning detracts from condition.

A soft bend or line in the paper caused by handling rather than a hard fold. Handling creases are condition issues that are more visible in raking light and can affect value depending on severity and location.

Materials — mats, backing, mounting, sleeves — that are chemically stable and free of acids that would otherwise yellow and degrade paper over time. Archival, acid-free framing protects a work’s long-term condition and value.

Premium picture glazing that combines high UV filtering with an anti-reflective coating, giving near-invisible clarity while protecting the work from fading. The highest tier of conservation glazing.

Glass or acrylic that blocks a large share of ultraviolet light to slow fading of inks and paper. UV glazing is a baseline safeguard for any work displayed in daylight or bright interior light.

A framing style in which the work is mounted on top of the backing so its full sheet — including a deckled edge — appears to “float,” with the edges visible rather than hidden under a mat.

The bordered card placed between the artwork and the glass, both to set the work off visually and to keep the paper from touching the glazing. Conservation matting should always be acid-free.

Recent sold prices for the same or closely similar works, used to estimate what a piece is worth today. Sound comps are recent, like-for-like on edition and condition, and drawn from actual sales rather than asking prices. See our comp methodology →

How quickly and easily a work can be sold near its fair value. Highly liquid works have deep, active demand; illiquid works may take longer to sell or require a discount. Explore the market data →

The first sale of a work — direct from the artist, publisher, or their gallery at the release price. Primary-market prices are set by the seller rather than by open competition.

All subsequent resales after the first — through auction houses, dealers, and private sales. Secondary-market prices reflect live supply and demand and are the truest gauge of current value. Read the buyer’s guides →

The winning bid announced when the auctioneer’s hammer falls, before fees are added. It is not the total the buyer pays — the buyer’s premium is charged on top.

A percentage fee an auction house charges the winning bidder on top of the hammer price. It can add meaningfully to the final cost, so factor it in before bidding. See what to budget for →

The confidential minimum price a seller will accept at auction. If bidding does not reach the reserve, the lot goes unsold (“bought in”).

The actual total paid for a work at auction — hammer price plus buyer’s premium (and any taxes). Realized prices are the real data points behind reliable comparable-sales analysis. See realized-price data →

An established, historically strong artist or work whose value has proven durable across market cycles. Blue-chip pieces are generally more liquid and lower-volatility, though never risk-free.