Study for the D-ABFDE by drilling the decisions the discipline actually requires: separating class from individual features, reading line quality before comparing forms, distinguishing hindered writing from disguise and simulation, knowing what light-based ink and paper observations can and cannot establish, identifying output technology before comparing printed defects, and expressing graduated conclusions with a stated basis. Work through produced writing samples and a self-check rubric rather than rereading notes.
Separating Class and Individual Characteristics When Comparing Handwriting
Class characteristics place writing in a broad group, such as a taught letter system, general slant, or skill level. Individual characteristics are the idiosyncratic combinations of proportions, spacing, and stroke habits that a sound identification opinion must rest on.
A taught letter system is shared by everyone who learned it, so it can never identify anyone on its own. Identifying value comes from combinations: how a writer crosses a t relative to the stem, where an a closes, whether spacing drifts under speed, and how these habits repeat. The underlying premise of the discipline is that habitual patterns persist while no single act of writing is an exact duplicate of another, so the examiner's core task is separating genuine variation from a genuine difference.
Apply this by charting, not eyeballing. Select recurring letters in the questioned material and mark the same letters across every available known sample. Check whether each questioned feature falls inside the range the writer's own exemplars display, rather than matching it to one convenient instance. A feature absent from a single known may simply be unrepresented; a feature inconsistent with every known, across all the writer's conditions, carries different weight. Write down which features are class-level and which are individual before you let yourself form a conclusion.
This habit matters because the distinction controls what a comparison can prove. Two documents written in the same school-taught style share class features; only repeated individual habits support common authorship. If your notes list class features as though they were identifying, your conclusion is built on material that could match thousands of writers.
Reading Line Quality Before You Compare Letter Forms
Line quality describes fluency, speed, pressure, and continuity of the stroke. It supplies the context for every form comparison, because hindered writing can mimic the slow, patched appearance that otherwise suggests simulation or a different writer.
Hindered writing arises from conditions: age, illness or tremor, an awkward writing position, a poor instrument, or an unstable surface. It typically produces blunt starts and stops, hesitation breaks, and shaky strokes, yet the underlying letter constructions remain those of the habitual writer. Simulation produces a similar drawn appearance but distorts the constructions themselves. Trace the difference at the habit level: does the poor execution sit on top of the writer's own proportions and pen lifts, or does it replace them?
Scenario: a questioned signature on a store receipt shows the same general capital form as the known signatures, and a hasty reviewer calls it an identification. Closer inspection shows blunt stroke beginnings, patched intersections, and pen lifts with retracing that never appear in the natural, fluent knowns. The better decision is to withhold an identification, examine the original under magnification for drawn-stroke evidence, request additional natural exemplars, and consider whether the writer's condition or a simulation explains the execution. The outcome changes entirely: the same letterform supports authorship in one reading and supports a drawn imitation in the other, which is why line quality must be assessed and documented before any form comparison is weighed.
Telling Disguised Writing from Natural and Simulated Writing
Disguise usually alters surface features first: slant, size, or letter style the writer considers most recognizable. Deep habits such as relative proportions, connecting strokes, and pen lifts tend to persist, while simulation substitutes drawn strokes for fluent ones.
A writer attempting disguise modifies what they believe identifies them, so the alteration concentrates on conspicuous features and is difficult to sustain. Over a passage of any length, the disguise tends to slip, and recurring letters written in different ways within the same document become informative. Natural writing shows the opposite pattern: fluency and internal consistency, with the same constructions recurring even when size or neatness varies. Simulated writing copied from a model shows drawn quality, blunt endings, patching, and inconsistency because the copier cannot maintain fluency while monitoring form.
Train this distinction by asking three questions of any questioned text. First, are conspicuous features altered while deeper habits persist, pointing toward disguise by the true writer? Second, is execution poor but construction habitual, pointing toward hindered natural writing? Third, is the stroke itself drawn, patched, or inconsistent between repetitions, pointing toward simulation or tracing? Each answer leads to a different investigative step, which is why these three conditions must be kept conceptually separate even though their surface appearance can look alike at first glance.
What Ink and Paper Observations Can and Cannot Establish
Non-destructive observation with oblique light, transmitted light, magnification, and filtered illumination can reveal indentations, erasures, alterations, stroke sequence, and differences between entries. Chemical ink analysis is a separate specialty with its own requirements and limits.
Learn each light technique by what it exposes. Oblique (side) lighting raises indentations and embossing from pages above or below. Transmitted light passes through the sheet and reveals erased areas, alterations, and differences in ink density. Infrared and ultraviolet examination, typically through a video spectral comparator, can make visually similar inks behave differently, revealing substituted entries or distinguishing two pens. Magnified inspection of intersecting strokes helps assess sequence, such as whether a signature was written over an existing entry. Build flashcards pairing each technique with the specific question it answers and its common artifacts.
Equally important are the limits. Two entries that look identical under one lighting condition have not been proven to come from the same pen or the same ink formulation, and an examiner should say only that no difference was detected under the methods used. Conclusions about when a document was written, or formal ink dating, belong to specialized instrumental work rather than visual comparison. Keep the two roles distinct in your notes: examining the document as a physical object, and comparing handwriting on it, answer different questions and support different statements in a report.
Distinguishing Toner, Inkjet, Typewriter, and Offset Output
Each printing and marking process leaves a recognizable physical signature: fused toner particles, inkjet mist, typewriter strike mechanics, or halftone dot patterns. Identify the production process first, then compare defects and characteristics within that process.
Scenario: a disputed agreement arrives as a PDF, with the signature said to be original wet ink, and a reviewer begins comparing the signature's letterforms. The better decision is to establish what the image represents first. High magnification shows perfectly uniform stroke edges with no pressure variation, no indentation, and pixel content identical to the signature block on a second document, with the image sitting above the text layer. That pattern indicates a digitally inserted image rather than an original inked signature. The finding matters because the correct opinion concerns how the document was produced, not who wrote the signature; comparing handwriting inside a pasted image answers a question the exhibit cannot support.
Use the same discipline for printed text: name the process, then evaluate features meaningful for that process, such as defect repetition in typewritten matter or consistent toner marks across pages said to come from the same printing run. A document that exists only as a reproduction limits what can be said about any original handwriting on it, so state that limitation explicitly.
| Process | Typical observable features | What comparison can address |
|---|---|---|
| Laser toner / photocopy | Fused, slightly raised thermoplastic particles; satellite specks and recurring machine marks | Whether pages may share a common source machine, and whether an entry is a reproduction rather than original ink |
| Inkjet | Fine droplet spray, mist at stroke ends, wicking into paper fibers | Whether an entry is original ink placed on the document, and consistency across entries |
| Impact typewriter | Strike pressure variation, ribbon impressions, repeated typebar defects and alignment faults | Whether documents may share a source machine and whether matter was added in a separate session |
| Offset / commercial printing | Uniform halftone dot patterns for images, plate-repeat defects across copies | Whether documents come from a common print run rather than being separately produced |
| Digital document / inserted image | Uniform pixel edges, no substrate interaction, identical repeated content, image layered over text | Whether a signature or entry is original ink or a digitally placed reproduction |
Expressing Document Opinions That Hold Up Under Challenge
A defensible opinion states its basis: what was examined, which features were compared, which alternatives were considered, and what limitations applied. Graduated terminology keeps the strength of the conclusion matched to the strength of the observations.
The discipline's established practice is to express conclusions on a gradation, from strong identification through qualified, indicative, or no conclusion statements, with elimination at the opposite pole. A reviewer challenging an opinion will probe the basis, not the label, so prepare to show the charted features and explain why each alternative explanation was rejected or retained. An opinion that overstates certainty relative to its observations is vulnerable precisely where an honestly qualified opinion is not, so practice converting any absolute-sounding statement into one with its evidence attached.
Procedural habits protect the opinion as much as the analysis does. Record what was received and when, photograph or copy material before handling, and note explicitly when only reproductions were available, because that fact limits line quality and indentation assessment. Preserve originals and return them in the condition received. These records let you answer, from notes rather than memory, how the examination was conducted, which is the question that determines whether your work can be reconstructed and relied upon by others reviewing it.
A Workable D-ABFDE Study Sequence with a Self-Check Rubric
Organize preparation around comparisons you produce and evaluate yourself, rotating through handwriting comparison, disguise and simulation, instrument-based observation, printing technology identification, and opinion writing. Check each cycle against the rubric below and repeat weak cycles.
An adaptable sequence: in the first block, master class versus individual characteristics by charting letters from your own writing across several sessions and conditions. In the second block, produce the exercise below and learn to distinguish natural, hindered, disguised, and simulated execution. In the third block, work through lighting techniques conceptually, pairing each with the question it answers and its artifacts. In the fourth, classify printed and digital output by process using the table above. In the final block, write full opinions with stated bases and graduated conclusions for every exercise you completed, then have the reasoning stand on its own when you reread it later.
Practical exercise: write one sentence three ways: naturally, disguised, and simulated from a sample of another person's writing. Set them aside for two days, then compare. Expected observations: the natural version shows fluent entries and exits with consistent slant and matching letter repetitions; the disguised version shows altered slant or size but retained proportions and pen lifts, and the disguise may slip between repetitions; the simulated version shows blunt starts, drawn strokes, patching, and inconsistency between repeated letters. Self-check rubric, each scored yes or no: (1) Can you list at least three habits that survived your own disguise attempt? (2) Can you point to drawn strokes in the simulation and name what makes them drawn? (3) Can you state, for each observation, what it supports and what it does not? (4) Can you write a graduated conclusion for each sample with its basis attached? Treat a full yes on all four as a learning milestone, not a prediction of any exam result; revisit any item scored no before moving on.
References and further reading
Use these references to explore the concepts and check the latest information from the relevant organizations.