Substrate waste in your printing business
The main causes of wasted substrate and how printing businesses can assess how much waste substrate is costing.
Wasted substrate at printing businesses can be attributed to a series of contributing factors that include:
- poor printing
- printing-head blockage
- poor set up
- operator error
- customers changing their requirements
- producing overs
- file copies
- a mismatch between the paper requested and the printing process being used
Digital printing can offer much lower waste levels than traditional litho printing, with the potential for no set-up waste and a minimum print run of one. However, digital print is often overprinted or produced in conjunction with other types of print, and may be trimmed and finished on conventional finishing equipment. Good substrate management can help avoid waste.
Understanding your substrate loss
The first step is to understand the amount of waste substrate and what it is costing you:
- Look what is in paper skips and bins - check regularly to ensure that your staff are not placing mixed waste in the paper skip as this can cause the load to be rejected, with loss of revenue from waste sales.
- Check what is in the mixed waste bins - if you find recyclable substrate then you will lose revenue from sales of waste, as well as data about substrate waste levels.
- Monitor the amount of substrate purchased and the average cost per tonne - keep track of the amount of substrate purchased as well as the value. Calculate an average cost per kilo, sheet or tonne and communicate this information so everyone is aware what substrate costs.
- Monitor the amount of waste substrate - calculate the amount of waste substrate using data from sales invoices. Calculate the raw material cost of the waste using average purchasing cost per tonne. Waste is caused by area loss (due to trim, finishing and die-cutting) which is part of the job design, and by sheets lost in the printing process. Take a sample of 'typical' jobs - perhaps ten to 20 jobs - and calculate an average area loss percentage for your mix of work.
- Estimate the process loss - deduct the trim waste from the total waste to estimate the sheets lost. You can reduce this by good stock management, process improvement and overs reduction.
You could also set key performance indicators (KPIs). These are measurements or metrics that help you to define and measure progress towards objectives and targets. Suggested KPIs include:
- KPI of clicks wasted = clicks paid for minus clicks invoiced. If your machine is leased then there will typically be a click charge for each sheet printed. Calculate how much wasted clicks are costing you.
- KPI of percentage of waste = waste substrate divided by substrate purchased x 100. This is a KPI for the production process and you can set a target to reduce this progressively over time.
- KPI of cost of substrate waste = amount of substrate waste times average cost per tonne minus revenue from sales of waste, plus cost of waste clicks.