Traditional woodworking marks

Question

A while ago I was watching this video and the guy casually mentioned some woodworking marks that I found to be really great.

I was trying to search for more of these today and found out they are sometimes called witness marks, among other things (I've seen layout, carpenter's, woodworking, witness, datum, and other terms used inconsistently to refer to these marks or various subsets of them).

I am now trying to find more about traditional, well-established marking techniques and symbols. It seems that it can be a fairly personal thing, for example in this book and this video of a guy sharing his grandfather's marking techniques, they use triangles pointing away from you, while the guy in the first video above uses triangles pointing towards you. Still, despite the personal touches, they all generally seem to be variations of a common theme.

The only marks I've really been consistent with up to this point are triangles facing towards me for alignment and a double squiggly line for the face side of a reference edge, both from that first video. I'll also be using the tally marks on joints now (I was just using triangles for that, too), since I watched the chiselandforge video.

My question is: No matter what you want to call them, can somebody share their knowledge of a full set of these marks? The chiselandforge link above covers a fair set, but for some reason this seems to be an ancient woodworking secret mysteriously absent from the internet (well, I couldn't find much). I'd like to know more.

^{As a sub question, which is actually what I was looking for to begin with: I'm also wondering if there's a common marking used to indicate an original piece in a series of copies (e.g. if I want to do the same thing to many boards, and I do my accurate measuring on one then copy it to the others, is there a traditional mark to keep track of the original).}

Answer 1

This is another example (of many!) where terminology is used irregularly in the woodworking world.

To me witness marks or witness lines mean lines such as you'd quickly pencil over a board face prior to planing or scraping, they then witness the progress you've made so that you can see where you have and haven't worked the wood yet.

Marks such as the triangle I know merely as alignment marks. Another system uses hatches, where you can use 1/2/3/etc. hatched lines to uniquely locate matching boards to their location for the final glue-up. I find this a little more useful than the common usage of the carpenter's triangle.

The other major marks used in woodworking are face and edge marking, also called datum marks.

If you find a need for any other marks I think you should just make up some that seem sensible to you. When you work in your own shop at home they only have to make sense to you, they don't have to make sense to anyone else so there's no need to adopt any accepted marks, and I believe there were some workshop-specific marking practices as well as regional or national marks, so lots of variation there anyway.

Of course if we go with the top-voted Answer on this previous Question we shouldn't be marking the wood where it shows in the first place :-)

Some more somewhat-related reading:
Setting-out basics on Geoff's Woodwork.

Answer 2

There are distinct sets of traditional marks for several purposes. At least some of the sets of marks have regional variations.

Reference face and edge marks

One common set of marks is a loop like a cursive lowercase l and an inverted v.

The loop marks the reference face which is the first face that has been flattened and levelled. All subsequent measurements will be made from this face.

The v marks the first edge that has been made at a right-angle to the reference face.

The tail of the loop meets the vertex of the v.

Alignment marks

Where two or more pieces of wood are being prepared to be joined, it is often useful to mark those pieces so that after working on them, you can tell in which way you originally intended for them to be aligned together.

This is typically done by putting the pieces together and making marks that span across all the pieces of wood.

lines

This has the advantage that you can use the number of strokes to number the joints. For example, when constructing a picture frame, you could make marks /, //, /// and //// across the intended joins in the four corners respectively.

triangle

This is used in some parts of the world more than in others. It is particularly useful when joining three or more boards edge to edge to make a wider board. It can be used for simpler cases also.

numbers or letters

Some woodworkers write pairs of letters, or numerals, next to one another on each side of an intended join. For example

 A | A

This can be useful where you have multiple identical parts (e.g. rails in a gate) but are hand cutting mortise and tenons or other joints that are fitted individually.

Obviously, this doesn't allow for an exact alignment, whereas as a line that crosses the intended join does.

Planing or sanding marks

When planing a board to remove bowing, twisting etc, it can be useful to scribble a line back and forth across the high spots.

When the planing has removed all the pencil marks, you know it is time to re-check the flatness of the board.