A writing instrument comprising a body having an axis, a writing tip, a reservoir and at least one visual mark being a specific mark for augmented reality applications, the at least one visual mark being configured to be hidden/visible when the writing tip is distant from a writing surface and to be respectively visible/hidden when the writing tip is in contact with a writing surface, at least a portion of the body being configured to allow the at least one visual mark to adopt two states, visible and hidden configuration.

A marking device that is supported by a personal mobility vehicle, such as a scooter, is movable from a first position, in which the marking device does not contact the riding surface, and a second position, in which the marking device contacts the riding surface. The marking device includes an attachment portion and a marking portion that creates markings on the riding surface as a result of frictional contact with the riding surface. The marking device can also include an actuation portion which is accessible to the user and allows the user to move the marking device to the second position. In one arrangement, the marking device includes an elastic marking member which is configured to bend in order to maintain contact with the riding surface.

Devices, kits, and methods for making a carved crayon are provided. In one aspect, a crayon carving device includes a base, a pantograph armature coupled to the base, a crayon positioner, and at least one guide template parallel to the crayon positioner. The pantograph armature includes a motorized drive shaft with a drill tip for carving an outside surface of a crayon body, as well as a guide tip for tracing along a guide template that directs where the drill tip carves. In some embodiments, the guide template includes a stationary bridge support and a plurality of removable carving bucks that insert into one of multiple openings on the bridge support. The surface features of each of the carving bucks may be traced by the guide tip to generate a corresponding carving on the surface of a crayon body.

There is a compound represented by the following formula (I):

##STR00001##

in which R1 and R2, identical or different, represent a C.sub.2-C.sub.30 alkyl group, a C.sub.2-C.sub.30 alkenyl group, a C.sub.2-C.sub.30 alkynyl group, or a C.sub.2-C.sub.30 alkoxy group, the alkyl, alkenyl, alkynyl, or alkoxy groups being optionally substituted with at least one hydroxy, halogen, amino, C.sub.1-C.sub.8 alkyl, or C.sub.1-C.sub.8 alkoxy group, as a temperature change regulating agent in a thermochromic ink composition. There also are thermochromic pigment microcapsules having a compound of formula (I) according to the disclosure, to ink compositions having such thermochromic pigment microcapsules, and to writing instruments comprising such ink compositions.

There is a compound represented by the following formula (I): ##STR00001##
in which R1 and R2, identical or different, represent a C.sub.2-C.sub.30 alkyl group, a C.sub.2-C.sub.30 alkenyl group, a C.sub.2-C.sub.30 alkynyl group, or a C.sub.2-C.sub.30 alkoxy group, the alkyl, alkenyl, alkynyl, or alkoxy groups being optionally substituted with at least one hydroxy, halogen, amino, C.sub.1-C.sub.8 alkyl, or C.sub.1-C.sub.8 alkoxy group, as a temperature change regulating agent in a thermochromic ink composition. There also are thermochromic pigment microcapsules having a compound of formula (I) according to the disclosure, to ink compositions having such thermochromic pigment microcapsules, and to writing instruments comprising such ink compositions.

A method for releasing impurities from a calcium-based mineral is described. The method comprises reacting a calcium-based mineral containing impurities with an aqueous solution of one or more ionic salts at a temperature of approximately 85° C. or above, wherein at least one of the calcium-based mineral and the one or more ionic salts comprises sulphate and at least one of the calcium-based mineral and the one or more ionic salts comprises ammonium, and wherein the concentration of the solution is approximately 25% or higher mass fraction, such that double salt crystals are formed and impurities are released. The method further comprises separating the double salt crystals from the impurities. Various products of the process are also described.

A core or crayon for writing and/or coloring has 15 wt % to 30 wt % of a core base material based on fat and on wax, and 40 wt % to 80 wt % of at least one filler, and 0.1 wt % to 30 wt % of at least one colorant. The core base material includes, based on the total mass of the core, 0.5 wt % to 10 wt % of aluminum distearate, 5 wt % to 20 wt % of oxidized polyethylene wax, and 5 wt %-22 wt % of at least one paraffin wax.

A marker ensemble includes a multi-purpose marking tool and a sharpener. The marking tool has a shell, retention sleeve, compression spring, control tab, reversible disk holder, and cap. The shell has an exit opening, an access opening with a mounting socket, and a medially located lateral control slot through which the control tab extends. The retention sleeve has a collet, compressed by the compression spring and uncompressed by the control tab. The disk holder has a body with a retention ridge and a pair of lugs extending from each end to retain a marking disk. One marking disk has a circular periphery and the other marking disk has a toothed periphery. The cap is mounted upon either end. The sharpener includes a blade with a sharpened edge secured to a body with an upper surface, a peripheral surface with a shoulder, waist, and hip, and a lower surface.

Devices, kits, and methods for making a carved crayon are provided. In one aspect, a crayon carving device includes a base, a pantograph armature coupled to the base, a crayon positioner, and at least one guide template parallel to the crayon positioner. The kit may further include a wrapper removal mechanism configured to remove a wrapper from a crayon, such that the crayon carving device may be used on an exposed crayon surface.

A wax-based coloring crayon for a porous surface and for a non-porous surface includes at least one wax, an ethoxylated fatty alcohol, stearin, a filler, at least one pigment, and optionally an additive.