06:52, the shutter goes up and the JV300 is switched on. 07:05, the first nozzle check of the day goes on the floor beside the waste bottle, and someone decides whether the morning starts with a clean or a flush. 07:20, the first roll goes on and the vacuum pulls it flat. 09:40, the wiper area starts to smell of solvent, which means the cap is not sealing as well as it did last month. 11:00, a damper comes off because one channel has been dropping out on long runs. 15:20, someone lifts the waste container and guesses its weight by hand. 21:10, the carriage parks and the last print is inspected under the shop light.

That is the consumables map of a JV300, and it is made of moments rather than part numbers. Every one of those moments has a part behind it, and every one of them costs more when the part is not on the shelf. What follows is a stock list, a skip list, and a way to set your own reorder points so the shelf reflects your machine instead of a distributor's warehouse.

The Stock List: Nine Items That Earn Shelf Space

Stock decisions are about downtime, not about discounts. An item belongs on the shelf if its failure stops the machine and its delivery time is longer than your customer's patience. Nine categories pass that test on a solvent machine like this one.

  1. Cap tops. The cap is the part that keeps the head alive overnight. Keep at least two, because a cap that stops sealing overnight turns into a clogged head by morning, and a clogged head is a much bigger bill.
  2. Wipers. Cheap, consumable, and directly responsible for how clean the nozzle plate stays between cleans. Buy them in the quantity you actually use in a quarter, not in the quantity that gets a volume discount.
  3. Dampers. Keep one full set for the channels you run, counted from your own machine rather than from a listing. A failed damper is a production stop, and dampers do not fail politely at the end of a shift.
  4. Cleaning solution and flush. Enough to do a proper head wash and a line flush without rationing. Shops that ration cleaning fluid pay for it in heads.
  5. Waste ink container or pads. Whatever your unit uses. Running a waste system past full is one of the few mistakes that can put ink where it was never designed to go.
  6. Encoder strip. One spare, stored flat and clean. You will not need it often, but when you do, the machine is down until it arrives.
  7. Ink in the colors you actually print. Buy to your job mix, keeping a buffer for a large order. Do not build a rainbow of cartridges that will age on the shelf.
  8. Consumable tools: lint free wipes, swabs, gloves. These are not glamorous and they are the difference between a clean maintenance routine and a scratched nozzle plate.
  9. Inline filters, if your machine uses them. Confirm against your parts diagram before ordering, then keep one set. A restricted filter looks exactly like a failing damper from the outside.

Quantity is the harder half of the decision. A workable rule for a shop that runs the machine most days is to hold one full change of the sealing parts, plus one spare of anything whose replacement needs a technician visit. Beyond that, let your own consumption decide, because a shelf that never empties is a shelf that owns your cash.

The thread running through that list is simple: everything on it either protects the head or keeps ink moving. Items that do neither belong on the next list.

The Skip List: Six Things That Quietly Tie Up Cash

Every shop has a shelf of parts bought for a failure that never arrived. Cash sitting in a box is cash not sitting in ink, media, or payroll. These six are the usual suspects.

  1. Printheads bought on rumor. Heads are the most expensive thing on the shelf and the most likely to be obsolete by the time you need one. Buy on a confirmed failure with a diagnosis, and check the date code and packaging when it lands.
  2. Full capping station assemblies when a seal kit will do. The assembly is convenient and expensive. If the frame and the mechanism are sound, the seals and the cap are what failed.
  3. Ink for colors you rarely run. Ink has a shelf life and a settling problem. Two cartridges aging in a drawer is worse than one ordered overnight.
  4. Media bought for a job you have not won. A pallet of specialty stock is a bet on a customer, not a spare part. Buy the roll for the job.
  5. Bundle deals that include everything. A kit priced to move usually contains the parts you already have and one part you cannot identify. Price the bundle against the three items you actually need.
  6. Boards, motors, and power supplies. These fail rarely and can often be diagnosed before ordering. Keep a technician relationship instead of a shelf of electronics.

The test for a skip item takes one question: what does the machine do on Monday if this box is not here? If the honest answer is nothing, the box is inventory rather than insurance.

If an item has been on the shelf for a year and the machine has not asked for it, that is data. Either the part is not a wear item on your workload, or you are carrying someone else's inventory plan.

Set Reorder Triggers From Your Own Machine

A reorder trigger is not a date. It is an observation that tells you the part has started to degrade, paired with a decision about how much runway you want. Build the observation first, then decide the trigger.

  1. Photograph a new wiper and a new cap top. Date the photo and keep it on the wall or in the parts file. Degradation is invisible when you look at the same part every day, and obvious when compared to a reference.
  2. Record the nozzle check pattern, not just a pass or fail. Save one image per week. A pattern that needs two cleans instead of one is telling you something about the cap, the wiper, or the damper long before it fails.
  3. Weigh the waste container on a kitchen scale. Write the number on the lid in marker. You now have a real rate of ink consumption per shift and a reorder point that belongs to your shop.
  4. Time the cap seal. Note how long a head can sit parked before the first nozzle check of the next shift shows dropouts. A shrinking window means the cap is going.
  5. Watch the damper ink column. A damper that is slow to refill after a clean, or that holds an air pocket, is on its way out. Mark the date you first noticed it.
  6. Write the trigger as an action, not a feeling. For example: order cap tops when the first nozzle check of the day needs a second clean twice in one week. That is a rule anyone in the shop can apply, including the person who does not usually run the machine.

Triggers built this way survive staff changes and supplier changes. They also give you a defensible reason to order before a failure, which is the whole point of holding stock.

The Fifteen Minute Monthly Audit

Once a month, before the first job, walk the machine with a notepad and no tools. The goal is to leave with a list, not to fix anything yet.

  1. Read the nozzle check history and count how often a second clean was needed.
  2. Look at the cap and the wiper against the reference photo, and note any change in color, shape, or stiffness.
  3. Check the waste container level and compare it to the weight written on the lid.
  4. Open the ink bay and look for weeping fittings, ink trails, or dried crust around the dampers.
  5. Run a finger along the encoder strip path with the machine off, looking for mist and for anything that has dripped.
  6. Check the media feed path for dust, adhesive transfer, and pinch roller marks.
  7. Count what is on the shelf against what the last three months actually consumed, and mark anything that has not moved.
  8. Write three lines: what to order now, what to order next month, and what to stop buying.

Then act on the three lines before the next job starts. Order the first item the same day, put the second into next month's budget, and physically remove the third from the shelf so it stops looking like coverage.

Do it on the same day each month and the list starts to predict itself. Fifteen minutes of looking at the actual machine beats a shelf full of guesses. A consumables map is not a document you download once; it is a habit of noticing which part is about to decide your schedule, and having it within arm's reach when it does.