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How to Use 2 Step Crackle Medium

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This article provides a clear step by step tutorial as well as some dos and dont's on how to finish your piece with 2 step crackling medium.


  1. Make sure the surface you're about to crackle is dry. Let glue/paint dry thoroughly before applying the 1st step of the glaze.
  2. Apply step 1. See tips below for info on cracks size/direction. Step 1 changes from milky to clear with some patches of white. It remains tacky at all times. It is usually 3-5 hours before you apply step 2.
  3. Cracks will appear after several hours; it varies depending on air conditions such as humidity or temperature (warmer is better, but do not rush it with a hair dryer). Best let the develop overnight, this way you let your work dry well before filling in the cracks.
  4. Use oil based glaze (here: liquid bitumen by Maimeri, also great for distressing and antiquing) such as artist oil paint to fill in the cracks. See tips below on how to successfully complete the crackling process with oil glaze and wipes.
  5. Seal with polyurethane spray varnish (2 coats), followed by 2-3 coats of acrylic varnish. You can skip coating with acrylic varnish if you are happy with the finish given by polyurethane varnish.


  • The thicker the first coat (step 1) the bigger the cracks.
  • When applying both steps, brush strokes direction determine the shape/size of your cracks. Practice on a piece of cardboard for different results; divide the cardboard (A4 size is fine) into 4 sections (use masking tape as borders). Apply a thin layer of step 1 onto the first 'testing field', don't go with your brush in the same direction, instead create e.g. a circle of step 1 in the middle of the field, and vary the brush strokes for the remaining spots, going from diagonal to vertical. Continue with the other 3 testing fields: vary the thickness of step 1, as well as direction and 'accuracy' of brush strokes for different crackling results. Make notes for future reference!
  • Remember to cover step 1 entirely with step 2 so that you're not left with sticky patches of step 1 that would never dry.
  • When filling in the cracks with spirit (usually oily and smelly stuff) based products such liquid bitumen by Maimeri work fast and by sections, i.e. don't smear your cracks filler onto the entire surface at once, instead take turns to apply some of the filler, wipe the excess of with a wet wipe, go to the next section. It is crucial not to go over the same spot twice either with your filler and (preferably) with the wipe. Otherwise, you risk ruining the crackle effect by dissolving the step 2 layer. So, apply the bitumen with a brush (liberally), and then quickly remove the excess with a wet wipe bit by bit. Make sure to rotate the wipe so that you only touch the crackle with a clean wipe each time you do the wiping off move. I use baby wipes, but kitchen wipes work fine... if only a bit too wet (some of them) and may remove too much of the filler along with the cracks. You just need to feel your way through it.


  • Do not seal your finished piece with acrylic varnish. Since it's water based it trigger off more cracks. And the cracking process starts again and you end up with a layered web of cracks. Instead, seal the cracks with polyurethane spray varnish (always work outdoors), 2 thin coats should do the job. Only then follow with acrylic varnish.

Things You'll Need

  • 2 step crackling medium
  • broad and flat brush
  • for filling in the cracks: oil based glaze such as artist oil paint, here I used liquid bitumen by Maimeri, my favourite antiquing medium by far
  • for sealing: polyurethane spray varnish, acrylic varnish

Sources and Citations

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