v3.26.1
Note 14 - Segmental Information - Schedule of Segment Reporting Information (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 28, 2026
Mar. 29, 2026
Jun. 29, 2025
Mar. 30, 2025
Jun. 28, 2026
Jun. 29, 2025
Jun. 28, 2025
Dec. 31, 2025
Revenue from Contract with Customer, Excluding Assessed Tax $ 95.7   $ 106.6   $ 181.4 $ 205.1 $ 205.1  
Other cost of sales (71.2)   (81.9)   (134.4) (158.9)    
Amortization         (0.4) (0.4)    
Share-based compensation charges   $ (1.1)   $ (0.9) (2.1) (1.8)    
Restructuring charges (1.6)   (2.0)   (3.8) (1.8)    
Other Operating Income (Expense), Net (1.2)   0.0   (1.8) 0.0    
Defined benefit pension charge (0.1)   0.6   (0.1) 1.2    
Interest expense, net (1.0)   (0.9)   (1.7) (1.7)    
Income before tax from continuing operations 6.7   4.9   11.9 12.3    
Loss on assets held for sale 0.0   (2.8)   0.0 (2.8)    
Disposal costs 0.0   (0.1)   0.0 (0.1)    
Restructuring Charges 1.6   2.0   3.8 1.8    
Segment, assets 389.0       389.0     $ 369.7
Segments, capital expenditures 2.6   1.8   4.8 3.2    
Operating Segments [Member]                
Revenue from Contract with Customer, Excluding Assessed Tax 95.7   106.6   181.4 205.1    
Manufacturing fixed costs (15.4)   (18.3)   (30.1) (35.3)    
Other cost of sales [1] (55.8)   (63.6)   (104.3) (123.6)    
Other segment items [2] (12.6)   (13.5)   (25.2) (26.5)    
Segment adjusted EBITA 11.9   11.2   21.8 19.7    
Amortization (0.2)   (0.2)   (0.4) (0.4)    
Share-based compensation charges (1.1)   (0.9)   (2.1) (1.8)    
Restructuring charges (1.6)   (2.0)   (3.8) (1.8)    
Other Operating Income (Expense), Net (1.2)       (1.8)      
Defined benefit pension charge (0.1)   0.6   (0.1) 1.2    
Interest expense, net (1.0)   (0.9)   (1.7) (1.7)    
Income before tax from continuing operations 6.7   4.9   11.9 12.3    
Loss on assets held for sale     (2.8)     (2.8)    
Disposal costs     (0.1)     (0.1)    
Segment, depreciation and amortization 2.2   2.5   4.5 4.9    
Restructuring Charges 1.6   2.0   3.8 1.8    
Segment, assets 317.5       317.5     298.3
Segments, capital expenditures 2.6   1.8   4.8 3.2    
Segment Reporting, Reconciling Item, Corporate Nonsegment [Member]                
Segment, assets 71.5       71.5     71.4
Segments, capital expenditures 0.0   0.0   0.0 0.0    
Gas Cylinders Segment [Member]                
Revenue from Contract with Customer, Excluding Assessed Tax 46.2   47.0   88.0 88.1    
Restructuring charges (1.4)       (3.6)      
Restructuring Charges 1.4       3.6      
Gas Cylinders Segment [Member] | Operating Segments [Member]                
Revenue from Contract with Customer, Excluding Assessed Tax 46.2   47.0   88.0 88.1    
Manufacturing fixed costs (6.6)   (7.6)   (13.2) (15.1)    
Other cost of sales [1] (32.0)   (31.3)   (60.0) (59.3)    
Other segment items [2] (4.4)   (4.1)   (8.5) (7.9)    
Segment adjusted EBITA 3.2   4.0   6.3 5.8    
Restructuring charges (1.4)   (2.0)   (3.6) (2.1)    
Segment, depreciation and amortization 0.6   0.9   1.3 1.7    
Restructuring Charges 1.4   2.0   3.6 2.1    
Segment, assets 124.4       124.4     121.8
Segments, capital expenditures 0.6   0.5   1.3 0.8    
Elektron Segment [Member]                
Revenue from Contract with Customer, Excluding Assessed Tax 47.3   50.1   89.4 99.5    
Restructuring charges (0.1)       (0.2)      
Restructuring Charges 0.1       0.2      
Elektron Segment [Member] | Operating Segments [Member]                
Revenue from Contract with Customer, Excluding Assessed Tax 47.3   50.1   89.4 99.5    
Manufacturing fixed costs (8.6)   (8.3)   (16.5) (15.5)    
Other cost of sales [1] (22.7)   (26.7)   (42.2) (54.2)    
Other segment items [2] (7.8)   (7.4)   (15.4) (14.8)    
Segment adjusted EBITA 8.2   7.7   15.3 15.0    
Restructuring charges (0.1)   0.0   (0.2) 0.0    
Segment, depreciation and amortization 1.6   1.6   3.2 3.2    
Restructuring Charges 0.1   0.0   0.2 0.0    
Segment, assets 186.4       186.4     171.0
Segments, capital expenditures 2.0   1.1   3.4 2.1    
Superform Segment [Member]                
Revenue from Contract with Customer, Excluding Assessed Tax 2.2   2.6   4.0 4.1    
Restructuring charges (0.1)              
Restructuring Charges 0.1              
Superform Segment [Member] | Operating Segments [Member]                
Revenue from Contract with Customer, Excluding Assessed Tax 2.2   2.6   4.0 4.1    
Manufacturing fixed costs (0.2)   (0.3)   (0.4) (0.7)    
Other cost of sales [1] (1.1)   (1.6)   (2.1) (2.6)    
Other segment items [2] (0.4)   (0.4)   (1.3) (0.8)    
Segment adjusted EBITA 0.5   0.3   0.2 0.0    
Restructuring charges (0.1)   0.0   0.0 0.3    
Segment, depreciation and amortization 0.0   0.0   0.0 0.0    
Restructuring Charges 0.1   0.0   0.0 (0.3)    
Segment, assets 6.7       6.7     5.5
Segments, capital expenditures 0.0   0.2   0.1 0.2    
Graphic Arts Segment [Member]                
Revenue from Contract with Customer, Excluding Assessed Tax     6.9     13.4    
Graphic Arts Segment [Member] | Operating Segments [Member]                
Revenue from Contract with Customer, Excluding Assessed Tax 0.0   6.9   0.0 13.4    
Manufacturing fixed costs 0.0   (2.1)   0.0 (4.0)    
Other cost of sales [1] 0.0   (4.0)   0.0 (7.5)    
Other segment items [2] 0.0   (1.6)   0.0 (3.0)    
Segment adjusted EBITA 0.0   (0.8)   0.0 (1.1)    
Segment, assets 0.0       0.0     $ 0.0
Segments, capital expenditures $ 0.0   $ 0.0   $ 0.0 $ 0.1    
[1] Other cost of sales includes material costs and variable costs.
[2] Other segment items primarily consists of sales, marketing, research and development, general and admin costs.