Three usual causes. You painted it over white or a light ground, and mica reflects whatever sits behind it, so any metallic that lets light through goes chalky over a pale surface. You scrubbed it on in every direction, which scatters the mica flakes instead of aligning them, so brush in one consistent direction. Or you thinned it with too much water, which separates the mica from the binder. Thin with an acrylic medium rather than water if you need it looser.

That depends on how much this one covers, and Graphite is opaque. A metallic that lets light through is at the mercy of its ground: over black or a deep grey underpainting it flares properly, and over white or raw canvas it goes pale and chalky. One that covers in its own right is far less fussy and will shimmer straight over a light surface, though a darker ground still deepens it. Either way, let the ground dry completely before laying the metallic over it in one or two even coats.

Yes, all Amsterdam acrylics are intermixable, but adding an opaque colour to a metallic buries the mica flakes in solid pigment and reduces the shimmer. If you want a metallic version of another colour, glaze a thin layer of Graphite over the opaque colour once it is dry rather than mixing the two on the palette. Mixing metallic into metallic works fine and is a good way to shift the tone.

Yes. The question that matters for selling work is permanence, and Amsterdam Standard Series is rated ++ or +++ for lightfastness with a 100% acrylic resin binder that cures water resistant. Where professionals tend to reach for a higher grade is when they need maximum pigment strength in a small area, or very specific single-pigment mixing behaviour. For large canvases, underpainting, murals and blocking in, Standard Series is a sensible professional choice.

Tell us within 7 business days of receiving it. Email customerservice@artshedonline.com.au with your order number and photos of the damage and the packaging, and our team will sort it out. Paint jars are packed to survive the trip, but couriers are couriers. Reporting it quickly with photos is what lets us make a claim and get a replacement moving.

Usually one of three causes. You painted a thick layer over a layer that was not fully cured underneath, so the top skinned and the bottom shrank. You over-thinned with water, which weakened the binder. Or you applied it very thickly in a hot, dry, windy spot so the surface set long before the body did. The fixes are: thinner layers, proper drying time between them, thin with medium rather than water, and keep a heavy application out of direct heat.

Acrylic paper or a heavyweight watercolour paper, 300gsm or above. Acrylic is a heavy, wet medium and lighter paper will cockle and eventually break down. Watercolour paper works well and gives you texture to play with, and stretching or taping it down first prevents buckling. Cartridge paper under about 200gsm is fine for quick studies but not for anything you intend to keep or frame.

Upright, lid on tight, at stable room temperature, out of direct sunlight. Heat and freezing are the two things that ruin acrylic, so a hot car, a tin shed in summer or an unheated garage in a cold winter are all bad storage. Wipe the rim before you close the lid or dried paint will stop it sealing. Never tip used paint from the palette back into the jar, because you are introducing contamination and half-cured lumps.

It can, though it takes mistreatment. Signs are a sour smell, visible mould on the surface, lumps that will not redisperse, or paint that has separated with a watery layer on top that will not stir back in. Contamination from dirty brushes and palette scrapings is the usual cause, along with a lid that never sealed properly. A skin on the surface is normal, just lift it off rather than stirring it in.