Alotofthings has 12 cc syringes (or were they 10?) with needles for about $1 apiece. If the tips are sharp follow grandad's advice. I just used a whetstone that I use for sharpening knives, chisels, plane blades, etc. i like using a separate syringe per color as I refill a whole set of carts and then wash out all the syringes at once. Gradad uses one and washes it out between refilling each color. Whatever you are comfortable with. If you want to absorb some of the cost of the shipping with additional items in the purchase you can order their refill inks. They are Sensient Formulab inks which I have not used yet but see excellent reports on from users of this ink from Alotofthings.