Starting from the top:
- A BOHIN mechanical pencil with white chalk. It can be erased. Write lightly, or you might fray your fabric trying to erase. There are also other colors of chalk available, as well as refills for the erasers and replacement leads for the pencil. These are made in France. They are highly recommended. Preliminary testing is successful, it erases cleanly. White is good for dark fabrics.
- A blue, water erasable pen. NOT recommended. The ink tends to bleed into the batting of the quilt and then come back to haunt you later, when you would rather it didn't. I have not tested this, there are enough horror stories around to make me not want to try it.
- A purple, air/humidity erasable pen that IS recommended. If there isn't enough humidity in the air to make it vanish, a swab with a damp cloth or a spritz of water works well. I have tested this. It is true. Purple does not show up on dark fabrics.
- A FRIXION pen specifically for quilters, sewers and the like. It writes green and a warm iron makes it go away. I have tested this and it is correct. I'm told it can be erased. No eraser is attached to this pen, but there are erasers on the ones you can get from an office supply store. Green does not work on dark fabrics. And I don't ever want to try to iron a quilt with polyester fiberfil batting. The batting melts into something like flexible cardboard. If I were to use wool or cotton batting and light colored fabrics, I'd try this pen.
- The square, white thing on the bottom left is tailor's chalk of the old school. It isn't really chalk, it is wax. The lightest touch of a warm iron and it melts. It leaves marks like oil stains on many fabrics. This wax comes right out with dry cleaning. Wax is wonderful if you are working with wool. It's not right for a cotton quilt top.
- The arrow head shaped doo-dad is a chalk wheel, that will put a fine line of (in this case) yellow chalk. The chalk brushes off and doesn't stain. For marking a quilt, it's only good for a very short time. The marks brush off so easily that normal handling, folding, and such will remove the marks. It is also difficult to get this shaped wheel to accurately mark a set of tight curves. Straight lines are easy. Chalk wheels are also available with white or blue chalk. The blue can be hard to find.
The qualities that are desired in a marker are that the mark be visible, the tool is not sharp and prone to damage the fabric during marking (super fine point tips are not always a good idea), and the marks should be either self removing, or easy to remove. If you choose not to remove the marks, they should not be visible to the casual observer.