In the process of evolving a signature, which must be again and again repeated from an early age till death, new ideas occur from time to time, are tried, modified, improved, and finally embodied in the design.  The idea finally worked out may be merely a short method of writing the necessary sequence of characters, or it may present some novelty to the eye.  Signatures consisting almost exclusively of straight up-and-down strokes, looking at a short distance like a row of needles with very light hair-lines to indicate the separate letters; signatures begun at the beginning or the end and written without removing the pen from the paper; signatures which are entirely illegible and whose component parts convey only the mutilated rudiments of letters, are not uncommon.  All such signatures strike the eye and arrest the attention, and thus accomplish the object of their authors.  The French signature frequently runs upward from left to right, ending with a strong down nourish in the opposite direction.  All these, even the most illegible examples, give evidence of experience in handling or mishandling the pen.  The signature most difficult to read is frequently the production of the hand which writes most frequently, and it is very much harder to decipher than the worst specimens of an untrained hand.  The characteristics of the latter are usually an evident painstaking desire to imitate faulty ideals of the letters one after the other, without any attempt to attain a particular effect by the signature as a whole.  In very extreme cases, the separate letters of the words constituting the signature are not even joined together.

A simulation of such a signature by an expert penman will usually leave enough traces of his ability in handling the pen to pierce his disguise.  Even a short, straight stroke, into which he is likely to relapse against his will, gives evidence against the pretended difficulties of the act which he intends to convey.  It is nearly as difficult for a master of the pen to imitate an untrained hand as for the untrained hand to write like an expert penman.  The difference between an untrained signature and the trembling tracing of his signature by an experienced writer who is ill or feeble, is that in the former may be seen abundant instances of ill-directed strength, and in the latter equally abundant instances of well-conceived design, with a failure of the power to execute it.

Observations such as the preceding are frequently of great value in aiding the expert to understand the phenomena which he meets, and they belong to a class which does not require the application of standards of measure, but only experience and memory of other similar instances of which the history was known, and a sound judgment to discern the significance of what is seen.

No general rules other than those referred to above can be given to guide the student of handwriting in such cases, but the differences will become sufficiently apparent with sufficient practice.