Celebrim
Legend
I'd be inclined to allow either Prestidigitation or some Cantrip specific to the task to mask the appearance of a held object.
Prestidigitation
Universal
Level: Brd 0, Sha 0, Sor/Wiz 0
Components: V, S
Casting Time: 1 standard action
Range: 10 ft.
Target, Effect, or Area: See text
Duration: 1 hour
Saving Throw: See text
Spell Resistance: No
Prestidigitation is actually a collection of very simple and basic spells, which can be cast repeatedly, quickly and without strain, and used in combination by a creative magician to create an almost endless variety of effects. In general, creating a particular effect requires a standard action.
Although you cannot use prestidigitation to change an item’s actual properties, you can use prestidigitation to slightly alter how something appears and is perceived. You can alter the color, taste, odor, and feel of an object as long as it remains in range. These changes are superficial and obvious to a trained eye, but can fool casual inspection or less keen observers. The effect of this is to give up to a -5 penalty on attempts on skill checks to appraise, detect or analyze an object, depending on the suitability of the change. For example, making a bit of clear glass appear to be a diamond is a suitable change, or making a bit of bad wine taste like good wine is a very suitable change.
Prestidigitation can be used to move items weighing up to a pound slowly, at the rate of 5’ per round. Light weight ropes can be ordered to knot or unknot themselves, allowing certain use rope checks to be made at a distance. It can also be used in this way to move dust or dirt off or on to objects or separate and sweep light objects into piles. Items occupying up to 1 cubic foot can be cleaned, soiled, or gathered in this way per round. Alternately, very light weight objects such as raindrops can be held at bay, as an umbrella of force. This screen is however insufficient to seriously impede actual missiles or even hurled stones. Prestidigitation can be used to move the air and create slight drafts or breezes similar to that created by a hand fan. It may also be used to slightly chill or warm a small object, but never enough to create pain or injury. By frequently creating cooling or warming breezes and other minor alteration of the environment the spell caster may grant up to a +2 circumstance bonus on any endurance checks provoked during the duration of the spell as a result of the elements. Because of the weakness of the spell, this bonus can be extended to at most the caster and one other person.
Prestidigitation can be used to teleport fine sized objects about ones person, for example, from one hand to another, from a hand to a pouch or back again, and so forth. It is commonly used for retrieving pinches of spell components from their hiding places.
Additionally, prestidigitation can be used to create small objects – usually no bigger than what can be held in a palm - out of thin air. These objects may appear like anything, but are easily recognized as artificial if held and inspected. They have no significant weight, cannot bear more than a pound of force, have no hardness, no hit points, and automatically fail any break checks. They may however be used to engage in any action that doesn’t require significant force, so for example largely functional needles, magnifying or reading glasses, cups, toothpicks, sponges, hats, quill pens, paper for temporary notes, spoons, and other small tools that are not used with great force can be created. At the end of the spell or whenever they leave range, the objects vanish.
When using prestidigitation to create an appropriate effect, the spell caster may gain a bonus of between +1 and +3 to various skill checks - most obviously bluff, craft, disguise, hide, open lock, perform, sleight of hand, and use rope. The spell caster must explain how the effect he is creating helps in this particular situation, with highly appropriate explanations receiving higher bonuses at the DM’s discretion.